First of all, I want to say I am so happy to see new content on this channel. Ted is a top-notch marksman and I have enjoyed these videos for years. Regarding the BC - why not put another chronograph at 100 yards and measure that velocity compared to muzzle velocity and calculate BC that way.
@@TedsHoldOver teddy you have done so much for us you have a patron or donation area? Shit I’d buy your only fans if you do weekly Airguns hunts on it😂
I believe you found the perfect speed and twist rate for that specific lenght and weight over that specific distance. In other words, the slug flies true through the trajectory curve for perfect aerodynamic angle of attack. No nose up or down during the flight through the trajectory curve. Just perfect. The choke of the barrel will also play a big role here on how it releases that slug (angle of attack). It's like finding a needle in a haystack, possible but very rare. Good football quarterbacks have the ability to throw, release and spin the football just right to achieve perfect angle of attack, speed and twist for optimal flight in order to achieve maximum distance with the least effort. Everyone who has thrown a football enough has at some point found that "feeling" of a perfect release. This is very difficult to achieve with a barrel in a gun. I believe you have found your unicorn.
@@Oregon-airguns agree, what Rolfe is saying is kind of right but does not explain Ted results. That’s simply down to incorrect data and operator error!
The inability to find the perfect ammo for YOUR gun is what makes these air guns nothing but cash cows for the manufacturers. You are all chasing the wind! Ted got lucky....after admittingly spending OVER 1K on ammo. REDICULOUS.
Hi Ted, First off I'm no mathematician but you might be forgetting about the angle change when zeroing, At the lower velocity you tilt the barrel higher to compensate for the distance to zero (50yds) if the velocity increases that angle changes to hit the 50 yds zero. I put your data into the Hornady calculator, here's what it says. 1000fps, BC 0.09, 26gn projectile, scope 3.75" above the bore, 0yds= -3.8", 25yds = -0.6", 50yds = 0", 75yds =-2" 100yds =-6.9". 1100fps, BC 0.18, 26gn projectile, scope 3.75" above the bore, 0yds= -3.8", 25yds = -0.9", 50yds = 0", 75yds = -1.2" 100yds = -4.5". 1100fps, BC 0.09, 26gn projectile, scope 3.75" above the bore, 0yds= -3.8", 25yds = -0.8", 50yds = 0" , 75yds = -1.5", 100yds = -5.5. I read somewhere that the location of the scopes reticle adjustment relative to the triangle created by the barrel and scope axis relative to the projectile start point will make a difference in the amount of clicks needed to reach zero (ATN web site I think), your rifle has the projectile a long way behind the scope reticle adjustments, in other words your adjustments are having a greater effect than if the projectile was below them
As an old high power rifle competitor, 200 to 600yds and 1000 yards. I am enjoying seeing you go thru the exact same testing to achieve the best accuracy you can from your equipment in an air rifle. Your finding that a pellet dia. in ten thousands of an inch can make such a huge difference in performance. My shooting was 50 years ago, and I heard of some top shooters that would go to the sierra factory and mic bullets coming out of the bullet making machine until the die wore down enough to get the dia they wanted and then take the next ten or twenty thousand bullets for reloading because that dia is what their barrel liked.
Thank you for the vid; it is quite stimulating --- which makes you the elite provocateur of thoughts, avvocato del diavolo, and rouser of enquiry into the logical/illogical world of Ballistics. This video shows that despite efforts to make sense of logistics with the behaviour of missiles, all pre-conception seems futile. You, sir, have dared to be the Sherlock Holmes of your vocation. "The only thing that remains constant is change," attributed to the Greek philosopher Heraclitus, seems to ring true in your efforts. To reiterate Mr. Holmes, "When one eliminates the impossible, whatever remains, however impossible, must be the truth". Thank you again your efforts. Stay well.
More Spin, Less Drag In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance. I think what you're seeing is your finding the sweet spot of the spin rate, ,this increased the BC which effectively increased the accuracy for longer ranges. I would almost guess the bullet as two sweet spots one low at the smaller BC and the one you have found...
I agree: it would make sense that a higher initial velocity, and greater rate of spin, would ccause more "lift" from spin "traction" as the bullet bites it's way thru the air. I love this stuff, as I've been an avid handloader for years, and the mysteries keep coming! "What we THINK we know, vs What we find in testing"
@@mikecollins8241 You, sir, are a THINKING man in the best sense. I have echoed your statements for the many years of searching for truth in all things in this world. Thank you for your maxim. Stay well.
The inability to find the perfect ammo for YOUR gun is what makes these air guns nothing but cash cows for the manufacturers. You are all chasing the wind! Ted got lucky....after admittingly spending OVER 1K on ammo. REDICULOUS.
So what about the drag increase in transonic region? At 1100 fps(about mach 0.97 drag on projectile at the muzzle is so much higher than subsonic speeds and its nothing to with spin rate or even type of the projectile (bullet,slug, airplane!....)what you saying could be true in supersonic projectiles like canterfire rifle bullets,but here we are dealing with subsonic airgun projectiles, clearly something is going on in this case,but as ted says, it must be impossible!!
Hi Ted. I just tested this with my LabRadar. I used the same barrel, 800mm 1:14 twist and same slugs, NSA 31.2gr .2165 . I shot a 15 shot string at 100yd. Average muzzle velocity was 1,087 and average velocity at 100yds was 941. Taking air temperature, station pressure, and humidity into account I got a G1 BC of .132. RA4 BC was .104.
For those looking to get the .2165's, keep in mind that the performance here is specific to his setup. Each gun has it's own personality so to speak and what works incredibly well in one will not work as well in another. Replacing a worn-out barrel or regulator, etc can and will affect performance with any load. You also need to consider lot number. For example, my M24 clone shot the first lot of Federal SMK BHTP 168 gr at an incredible 1/3 MOA. When I moved to a different lot of the same load the groups opened up to 3/4 MOA. So, definitely consider the load(s) Ted is recommending, but YMMV.
@@tadracket448 let me give you some advise. Steeer clear of fx… take a look at the Vulcan 3. It’s a straight killer right out of the box. Shooting avs slugs. M channels not nearly good as teds. But I’ve been down the fx road and it was a total nightmare.
Internal ballistics are a funny thing. Barrel whip can throw the same bullet to two sweet spots at different velocities. The first (lower velocity) shot may be whipping the muzzle down slightly and giving you a stable muzzle exit at with the muzzle low. The higher velocity may be throwing your groups higher. This gives you a different number to calculate BC than the 'accurate' number. You'd have to check velocity at multiple points on the trajectory and see if the velocity is dropping with the BC. The other alternative is that the BC is changing due to transonic interactions with your bullet profile. Bullets do weird things whey they try to push air around them at supersonic speeds, even though the bullet itself isn't supersonic. You could be getting a better BC because of the supersonic flow characteristics of this particular profile. Me, I avoid transonic as much as I can. With my .44 Magnum rifle loads, I stay at about 1,050 FPS. Bullets that fly much faster risk running into weird stuff, as you may have experienced. Only strike against this theory with your bullets is that they slow down REALLY quick to full subsonic flow.
yeah, you missed the point - he measured the difference with the same velocity 1100 at 100 and 50 and compared the difference. Pay attention, focus and don't speculate
Ted for me this has just blown my mind your dedication to education of the masses is incredible, thank you . Keep doing all that you do especially nailing the pigeons.
The air bubble on/in the HP is trapped creating a "tip" on the slug. The higher the velocity the more efficient it becomes because the air bubble is under more pressure from the on coming air. This in turn lowers the resistance the actual slug is facing because of the twirling air inside the HP is under more pressure getting push through the atmosphere by the slug. High powered rifles used for competition shooting use hpbt and not pbt rounds for this reason. How fast is to fast before this has diminished returns? I don't know but with pcp's it doesn't matter but clearly you have just proven that this effect starts to really have benefits around 1100fps and not so much below 1000fps.
I really enjoy listening to ballistics nerds (like you and Matt) heading into the weeds of researching and explaining what's going on with slugs & pellets in flight. I'm not sure what percentage I'm missing, but it's fascinating watching you work on it.
That's what I was gonna say but you condensed it nicely. Wonder if the shockwave forming in front of the slug is displacing some of the air, or letting the slug ride the lower pressure air right behind it. Also the group tightening with the increased speed can be due to barrel harmonics and (or) a reduced follow through time.
Wonderful video, I've been playing with the neilsen slugs in 21 and 23 grain in my Avenger, I upped my reg pressure about 150 psi to 2250, and I noticed a drastic difference in the amount of drop beyond 75 yards..much more so than I'd expected. Now I'm enjoying some flatter shooting, but I've yet to push them across the chrony..that's the next step 😏 thanks for another great video, appreciate your dedication to the airgun community and sharing what you learn.
I've also ran into many ballistic "mysteries" but in the end they were simply not taking into account of atmosphere conditions or user error. Temperature and altitude density have HUGE affect on BC/trajectory. Zero one day and not readjust to new weather condition into the ballistic calculation will through you off big time. I've learned the hard way and always validate zero and reset atmosphere conditions in ballistic solver with minimum local weather station information, I try use a weather meter for my ballistic solver and make a point to update the information EVERY HOUR! Ted: Love your show and learned a ton from you especially on tuning the gun. Keep up the great work!
BC is defined by change in velocity between 50 and 100 yards. Delta in POI could be deceptive because it includes the effect of barrel harmonics. Summary of insightful statement by RyeOnHam
nope, what he wrote was dumb because he doesn't pay attention and makes up crap that sounds smart to other people that don't understand basic math and don't pay attention. Barrel whip is not a variable because he was shooting at the same speed at 100 and 50 yards. The barrel harmonics doesn't change because of the distance you shoot or because you aim at different thing....
You're going to LOVE that wildcat. I grab my WC a lot more than my impact or any other rifle. It's just the perfect balance of comfort/accuracy/power. If someone were to ask what their first FX should be, I would recommend the Wildcat BT, hands down.
Great video Ted ! I’ve watched you from the start , and you got me with you never ending quest for top performance. With the right equipment, and understanding the science the hours you spend on target make it all come together .thanks for sharing your system and how it works ! I’m still amazed at shooting nickels at that distance………with air…….. !
I remember when I was a kid, my grandpa would talk to me about a “magic velocity” for his .22 cal while I sucked feverishly on a werthers original. He was a professor in physics and told me some jibberish about how at a certain velocity and twist rate, outward forces such as the effect of wind and even RAIN would have little to no effect. Those numbers I suppose, would apply to slugs from an air gun as well. Matter of fact, I know they do “;) Dam, those Werther originals are good…
I wonder if the air hitting the hollow point at that speed combined with entire shape of the projectile is creating some form of aerodynamic effect that is producing this. Or maybe airflow that is hitting resistance just before transonic across its body is stabilizing it even more? Who knows? The only thing I know is that I'm excited to see more!
High powered rifles in competitive shooting use hp rounds bc of this effect. It causes a high pressure air bubble on the tip that goes through the atmosphere more efficiently than a pointed tip does. His data is showing that somewhere above 1000fps is where this effect shines
Rotation of the slug makes the air travel a longer distance along it. This would make the slug virtually longer. With 335m/s the slug should rotate about 20k times per minute.
Hi Ted, What you are observing is the effect the speed and hollow point has on the BC. Higher the velocity of the projectile = higher BC and the hollow point traps air (bubble) and the higher the pressure the harder the bubble is and the more it's aerodynamically shaped which results in reduced drag and higher BC. Mythbusters "golfball effect" and "tailgate" has very nice visualization of the phenomena.
Good to see you back Ted!! On the BC is it possible that the hollow point is creating a slip stream affect like a pickup truck box does with the tailgate closed air moves freely over the truck. With the slug the cup fills with air that is compressed whether going fast or slow causing the slug to stabilize.
Probably the same concept like an arrow flying. You perfectly found the speed needed to stabilize the slug in the air. When a arrow is shot at a slow speed the fletchings need to be larger to get the same bite as the smaller fletchings at a higher speed. Like a fighter jet. They use 100% power as slow speeds because they are falling from the sky. When they actually get to optimum flying speed they stabilize. I'm pretty sure that's what you are witnessing with your slugs.
to a point but if the bow is correctly tuned the arrow will fly straight with no fletchings in other words the only thing on the shaft is a nock and a field point and no fletchings that is the correct way to tune a recurve or longbow it must be in harmony
Hi Ted, great info on the airgun and new slugs. That is pretty cool what you are getting with these slugs! I had one thought which is - why introduce the scope change into your calculation? Simply shoot at 50 yards and it impacts the target, you can make it near zero but quite honestly it does not destroy the point of aim if it hits a few inches low. Then simply back the target up, continue to shoot at the same aiming point. Measure the difference between the two groups and you have the drop at 100 yards. The aiming point is quite irrelevant so long as the aiming point is the same each distance, I actually prefer to make a cross with a heavy marker or even tape depending on what I am doing. That way no scope calibration issues are introduced, etc. The drop is what the drop is. Just have to shoot at the same point, leave the scope alone. Keep on killing those starlings!
Great stuff here Ted you will find that the 1:14 twist shoots really well out at farther distances and the faster twist has a lot to do with that BC number you came up with here
Good god! Your still the goat! I was like 👍 2k btw. I’ve noticed the same thing with different lots of 22lr some lots come out to .170 bc and others .123 same exact bullet, even weighed them. Billets we’re Norma Tac they vary in velocity a lot from lot to lot. Some lots 950 others 1100. Thx again Ted!
Ted, I have encountered something similar to this shooting .216 KOs when upping the speed from (normal) 960 fps to over 1020 fps. Had to change the BC from .89 to 1.25 to get Strelok to "match up" predicted vs actual POI. Didn't make sense, so I re-checked all my input data and found that the scope height value was no longer correct(by shooting a target 10 yards away) when shooting at the higher speed. When I input the new scope height and returned to using a BC of .92, all the Strelok click info "trued up" again. You can test if your scope height is correct or not with your new faster setup by shooting at a target that is much closer(10 or 15 yards) than your scope zero(50 yards) where BC doesn't matter that much. See if the Chairgun predicted holdover match actual POI or not.
This is the channel that got me to buy my first large bore air rifle. I wish I could afford a higher quality one because I have a Benjamin and it's not super great or super accurate..
Ive watched you since the edgun matador days. The 130 yard pigeon shot got me into the air world. Ive got an impact m3 .30 cal shooting knockouts 900-905 sub moa out to 150. Jsb pellets 50.15 gr also mostly moa to 150 with some flyer. Stx standard barrel @910-915. Wish I could post pics here. Great to see the content again
Hi Ted, great to see you back, making a fantastic video and sharing your knowledge/information with us again. I’m shooting Neilson’s (as I’ve found these the most accurate 24.8gr 217’s) out of my M3 700mm superior @ 974f/s. Zeroed at 50m, they are bang on out to 80m then start to go a little sketchy beyond that. Maybe I need to get them going a little faster?
I ran a trajectory test on the .177 JSB KnockOuts, with a posted BC of about .047 at 970 FPS. Then I fed the data into Strelok Pro. Of course using the BC provided by JSB didn’t match the real world data I’d collected, so I used the BC truing function and came up with a BC closer to .09. The shot chart in the app was within a click of my data as far out as I had data so far collected. BC is speed dependent. Are manufacturers shooting at slower speeds? Are they using a conservative “at least this good” number? Are they calculating over longer distances which leads them to use a lower average speed in the calculation? Is Wisconsin’s dairy air magically slipperier? Thanks for raising questions Ted!
I am seeing exactly the same. FX Maverick 700mm, Superior liner, H&N HP 27gr .218. Claimed factory bc 0.95. @920fps I see bc of .097, when I crank them up to 1000fps bc leaps to 0.131. Used same method to verify as you did, also did verification at every 10m from 40m zero all way to 100m. Not complaining, but shocked me. Just managed to get first supply of H&N HPII 27gr Slugs, so will need to try with them???
Amazing Ted! Would be interesting to try another barrel (the same) and see if you get the same results🤔 This would then show you have found your nirvana combination. Also cleaning the barrel to see how that affects your groups. It is amazing how far air rifle technology has come in a few years! Great video!
Calculate the arc of flight, trajectory. Find the highest point and sight in zero at that distance. If you shoot further adjust up AND the closer you get you will need to adjust up again.
I only shoot pellets, but I still adjust my BC to get it spot on. And I have yet to find a manufacturer BC that's actually perfect. And the BC I end up with after shooting/testing a pellet is always lower than what they say! The actual BC number is kinda weird to me because just to change the POI an inch at 100 changes the BC number a lot! But I don't really care what the number is, or how my BC compares to the one given by the manufacturer... all I care about is that it's correct for me! Thanks for the video! I always enjoy listening to you & learning! ✌️
Yes! It is possible. Getting closer to the SS - the lower is density of air flowing along the projectile. That means : less drag, more BC. A firearm bullet has his BC if the speed is above the speed of sound only.
Hi Ted, i know this is an old (relative post) but hers is my idea, the ballistic coefficient on some shapes of "slug" is NOT LINEAR !! as the slug approaches the speed on sound and we know the destabilisation issues of traversing the speed of sound. Drag is caused by the air stream going past the side of the pellet. The nose of the slug or pellet builds up a pressure cone in front that helps the airflow around the projectile. But it still allows the air to slide down the projectile so your changes in speed are affected by the shape and "balance" of the projectile. ( look at a Sherman tank shell when fired, its not flying straight !!! but pointed up slightly against the ballistic curve !!) but that's not the point, im just saying different projectiles act differently. ( How some pellets FLY by different shapes and C of G positions is another subject) The air stream is working with the projectile shape and affecting its coefficient as a result but in a linear fashion. Up to a point, When you are very close to the speed of sound and you were right on the edge, you are now starting to create a real shock wave and although the airstream is not creating a sharp edge that produces the destabilisation and CRACK sound, it HAS created a deflection in the airstream that has started to leave the side of the pellet.. that's where the shockwave phenomenon starts by the airflow leaving the side of the pellet, and moving forward eventually creating a hard shockwave. This is what changes the coefficient dramatically from the predicted drag figures.. suddenly the drag drops in this small zone when the speed increases. Inversely when the speed drops around this point the drag slope changes and drag increases as the skin effect is re-established. This reverse curve is only there for a very slight variation on speed and is dependant on the profile weight and C of G of the projectile. This is why Chuck Yeager had the reverse control phenomena just as he approached the speed of sound, and had to fly through it by increasing the speed to regain control. Also affected by temperature, humidity and earth rotation etc. it's not a useable zone as the natural drop in speed over a few tens of meters will have left this variable zone.. That's why aircraft don't fly just below the speed of sound in that slightly better efficiency zone because it's so small.. Ive watched all of you videos and loved and learnt from all of them, and ive seen you shoot shell casings at the range just a little too hot where some pellets were flying dead straight and others were getting destabilised as they were affected by traversing the speed of sound. You said then that they were a little hot, and we all know the effect, but the little blip just before this critical speed is affecting the drag coefficient and upsetting your figures...just lower the speed by 10 fps and the curves will be predictable again. That's my theory, I do electronics and there is often a negative reaction in oscillations just before a positive one. colin
Here is the response I put up on my group Precision Airgunning So, does anybody want the answer and explanation? Its really quite simple! Ok So, Teds theory of a .22 calibre 30 grain slug with a manufactures published BC of 0.095 having a BC of 0.180 is not only wrong, but absolutely bonkers. So lets start with some basic ballistics. Using a G1 standard BC drag models the BC is not fixed, it is in fact dynamic and changes with velocity and bracketed into velocity bounded segments. BC is normally the first thing an inexperienced user/shooter will manipulate, mainly because its the one thing that they least understand. I mean people find comfort in that they believe their velocity is 100% correct because their chronograph tells them so, we wont go into chronograph read error in this subject but just keep in mind that it does exist! A few other things to keep in mind on this sort of situation is - Range error, velocity error, environmentals, false zero and scope tracking error, to name a few, they all exist. Anyway moving onto the mysterious issue that has got all the top dogs confused! In shot ill just go out ad say it - Scope height, yes it is that simple folks an here is why. If you look firstly at Ted's Rifle set up he has a Saber Tactical back bone rail with inbuilt 20/30 MOA built in, some sort of scope base with built in adjustable elevation,, scope mounts and then the scope, just look at the scope height its crazy high. Then move over onto his Chairgun Pro data where his inputted data states that his scope height is 3.75",crazy high! Essentially what this is causing is excessive or an acute angle with regards to line of sight relevant to bore line. So some more basics, when any projectile leaves the bore regardless of velocity (500 - 4000fps for example) the projectile slows down and and begins to fall away from the line of sight (Gravity) immediately and continues to do so. So how do we hit targets at 100,200,500,1000 yards away, well we add trajectory into the equation via the scope, effectively adding ark into the equation, or lobbing bullets in laymen talk. So in order to order to hit a target at distance the projectile has to leave the barrel and leave the bore line to meet or match the line of sight, (primary (1st) or secondary (2nd) zero) With airguns, because generally they are used at closer ranges when compared to long range centre fire rifles we have to be a little more, lets call it aggressive with the angle created through our scopes in order to match our POA vs POI. This only seems to effect airguns, largely because of what I said above and their close range usage. Im sure some of you guys who shoot either sub 12ftlb air rifles, or a better example is night shooting close range rats at say 20 yards with a perfect 20 yard zero, notice how if you aim directly at a 30 - 40 yard rat you will shoot clearly over the top of it, but then a 50 -60 yard rat you can aim straight at it and hit it, this is the primary (Close) and secondary (far) zeros \I was talking about before. In Ted's situation he has come across the exact same problem but at just a further distance out, this is due to his excessively high rifle scope. To meet his 50 yard zero he will have to have some serious angle dialled to mach his POI vs POI. Once he shoots and hits his zero at 50 yards, the slug, particularly at higher speed will shoot through the line if sight and continue on its upward path above the line of sight to around 70 yards before coming back down through the line of sight back town to his distance of 100 yards. this gives the impression that the projectile is shooting flatter when it is not, its just got a greater arch due to the excessive built in scope height. I hope I have explained it in a way that it can be understood, ill add some Strelok screen shots to demonstrate that just by changing scope height can manipulate the POI down range. Ted simply has just hugely manipulated the BC value of the projectile to the point that it matched his real world DOPE - wrong on every level! I hope this clears this mystery up, just take note that we can simply explain Ted’s findings by simply matching his Correct scope hight and manipulating various scope hight settings to vary results and not BC, if you take one thing from this, make sure you pay attention to scope hight!
You can get the same results by slightly altering far zero. Also when he shot his 50 yard shot after dialing 5moa for 100, his shot at 50 is exactly 5moa high.
Another great video Ted. I have more experience of centrefire projectiles and its common for the BC to change with velocity so no surprise here. Keep up the good work !!
First let me say Ted, I love your channel/ posts, Keep it up. Thank you. This is a great example that shows that BC is not a constant as is too often believed. This might be an example of better stability. or I will have to refer to the boys at Sierra bullets. Sorry I cant put it into words but give them a call they will explain this very well, how or why BC IS dependent on Velocity. There are computer simulations that show what the air does around a projectile in flight at differing velocities I just can not find one right now to refer you too. BE
I think it distinctly possible that the poi shift could be attributed to a difference in barrel harmonics between the 2 power outputs. when the 1000 fps group is considered the base mark, the calculator would naturally assume that the slug maintains a higher average velocity (due to a higher bc) but, if the harmonics of the gun are altered enough then the barrel could be letting the slug out at a different angle than before (which is assumed to be 0 in both instances in your calculations). Just a thought but it could also explain why the difference between the gap in your 50 yd and 100 yd zero (from 1000 to 1100 fps) because the parabolic curve of the trajectory is such that if the two zero points were both closer to the apex of the trajectory then the change in Y (as it were) would naturally be less. Tell me if I'm off the mark with that though
Ok, got it figured out i think. If you punch in a 58yrd far zero in chairgun, it puts you .15in high at 50. Close enough right? But it then kicks you up to less than 5in drop at 100, without messing with the bc at all.
The .216 is amazing in my Liberty and my Avenger. The .2165 isn’t to bad either but not as good in a Nova Vista barrel. Really happy around 900-940 with 20.1 grain. That said they my not like another barrel from the same company. Pays to buy variety when testing👍💯. All that aside I believe what your experiencing has to do with twist rate, sectional density, and speed. A slower twist rate and lower velocity will produce more drag if I have my head wrapped around this right. Hopefully you will do a follow up video on this.
Chris Turek did some groups at around 1200 fps. He had some pretty good success I thought. There is potential for airguns to operate at supersonic speeds. I get that the whole point of air is to keep it quiet, but I'm absolutely sick of everyone defaulting to "you can't shoot air projectiles over 1000 fps, it won't work". That's a pile of malarkey. I truly believe you can and it's going to become a lot more normal one day.
To be clear I'm not saying you can just launch things out there at 1400 fps. I think you need several things in harmony to still maintain good grouping / accuracy / precision. Most important being twist rate. What's perfect for 100 yards may not be perfect for 40 or 50 though. Everything is a trade off. Either way, keep pushing the envelope Ed. You're work is, and always has been quite important and we appreciate you.
Interesting. Before searching for a reason for which your calculated BC has almost doubled, maybe its worth: trying another rangefinder / another chronograph / confirming your results at 200y (you would probably get a lower than double BC) / trying to shoot without the moderator. Or maybe the change in rifle harmonics is moving the barrel up when pellet exits the gun, not very noticeable change in zero at 50y but more pronounced shift of poi at 100y ? Great video though.
I agree with some of the other comments... at 1000 ft/sec the slug might not be fully stabilized and thus is wobbling slightly with increased drag, thus the lower BC. The additional RPM given by the extra 10% of velocity is fully stabilizing the slug, hence the lower drag and higher BC. Interesting though, that a standard .22 LR 40gr bullet is expected to be fired through a 1:16" twist barrel and to be stabilized. I wonder if this is too low, and if we might see more accuracy from .22s with 1:14" or even 1:12" twist barrels.
Try a harmonic stablizer, move it up and down the barrel and see if you get a change in grouping. That would rule out that variable if you dont see a drastic change in grouping.
Some good comments here!! Another thought I had Ted, speaking from an engineer's standpoint, is to confirm your data to make sure nothing is lying to you. Specifically in this case, would it be worth calculating the BC based on Vo (initial muzzle velocity) and V1 (velocity measured at impact)? Unless I missed it, you're currently only measuring one velocity (I assume muzzle, since I'm not 100% familiar with your equipment), and we don't know what the other velocity is (in this case I assume at the target). Maybe your app works such that it's measuring the delta in sound from gun firing to impact, in which case it's inherently measuring only one velocity. Although it's a bit risky (shooting your chrony), I've placed mine at the target in the past after knowing muzzle velocity, so I can then measure target velocity and confirm manufacturer's claimed BC. Anyway, just a thought to ensure your data! 🤙 As we say in engineering, garbage in garbage out! 😜
Hi Ted. You're the man broseph. Come on out to new Hampshire and we'll rip up some grey squirrels. I love all your videos I love how you get in depth and explain all the math in a way that's made simple. Keep up all your good work and keep up all the videos Ted. You are the balls and I always look forward to your next video. Let me know if you are ever in New England we can tear it up
BC is comprised of a bullets sectional density and its form factor. Form factor describes the drag of the bullet in comparison to a standard. The old G1 standard is not representative of modern bullets in terms of how its drag changes with speed. So, as velocity increases, the drag of modern bullets is lower than the standard, so the form factor decreases at higher speeds, which means the BC increases.
Hi Ted , really great and interesting video, with that BC confirmed at 100 yards and add to the fact that the slugs are shooting 100 plus fps faster than what Nielsens do at say 1000fps I think it would be safe to say that you are flattening out the trajectory or ballistic curve , so then enter your average speed into something like strelok shoot at say 200 yards or even at 250y which ever you feel comfortable with but it has to be quite a bit further than 100 yards and see where strelok tells you to dial for say 200 or as far as you are willing to shoot and see if the ballistics match up , the reason I say this is because if 100 yards is the longest distance you are going to shoot then that’s great but like most of us we all like to test ourselves to hit things further away whether that’s cans of pop golf balls or hunting you will need to see how that BC matches up to your turrets at further distances , sorry if this is a boring long ass comment lol but I would like to hear your thoughts on it , all the best G.
Thank you. Yours is the information I trust the most and look forward to each installment. My M3 factory 700mm shoots pellets great but is giving me fits with slugs. Not sure where to start. 22cal.
Barrel harmonics and actual sight height above boreline, perfect spin rate for optimal BC and finally the transonic airflow to the rear of the projectile should be considered.
its possible, and a known occurance with certain shaped projectiles. considering g7 drag model and how its averaged over mach 1.75, 2.0, and 2.25. doppler tracking projectiles brought light into this stuff.
First thought (layman speculation) is that it's related to being transonic; maybe see if the bc is still as high when calculated between 100 yds and 150 or 200 yds after the slug has slowed down a bit.
That's my guess too. It's really close to going super sonic (maybe closer than he thinks because of atmospheric conditions) so there's a pressure wave or whatever in front of it, displacing air.
Bryan litz just started testing airgun projectiles. I’d shoot him an email. There is literally nobody on the planet more knowledgeable than him on this subject.
Hi Ted, spoke to you the other day about your finding but the comments appear to have been removed. Ive listed them in my group Precision Airgunning if you wanna take a look.
Yay keep the vids coming been watching since the beginning. Maybe have a question what do you think about the fx dreamline power pup. Been looking into it and wondering if .22 or .25 which would be better for shooting a combination of slugs and pellets
Hmm, seems yt didn't post my comment because I linked to a paper. (Estimating Transonic Drag) In any case, here's a clip from their abstract which should explain what you are seeing. "For the most part, the drag coefficient (which is dependent on the local Mach number) is well-understood for subsonic and supersonic velocities. However, there is often a rapid and unintuitive change in the drag behaviour near the speed of sound."
I think in order to figure out what's going on with the bc you need to have more data. At very least have final velocity at 100 yards. It could be that as speed increases, the spin also increases making the slug more stable. If there's even a little bit of weeble wobble it will have to push through more air during it's flight even though it's traveling an equal distance.
Putting it simply, the G1 reference drag law is not suitable for slugs with a large meplat, particularly at speeds over 1000ft/sec, and measuring drop should never be used for calculating BC as it is the most inaccurate method. Your results are basically showing up the large problems with still using the BC system for calculating pellet and slug trajectories. You don't need any theories about shockwaves and spin rates to explain it. I did write a much more complete explanation, but it seems to have disappeared.
Cant input with your slug info as I've got a wolverine 2B hi-lite that doesn't shoot slugs well (Or i haven't found one yet, just bought 216 JSB not tested yet). In the video you said that MOA is about 1" at 100yds, (1.047") I've got a Helix and Titan ( Bought from Giles airgun 101 in the U.K. awesome scopes.) mine are in in Mrad but I'm surprised that Element didn't use SMOA in their MOA models to help with the maths, is there any reason why they wouldn't have gone with the 1 click is 0.25" SMOA @ 100yds. Love it when Ted is buzzing about things again. Ted the legend that is. All the best Wales U.K.
Take the new bc and test it out at distance. 200 or 300 yards. See if the ballistic calculation lines up with using the new bc. Mathematically it would make sense that the bc has changed because it isn't impacting where the .09 is predicting. Which would make sense if the bc of the slugs is based off of 1000fps testing.
I don't know what's happening either... but I like it. ;) What it means to me is that shooting slugs 200+ yds without massive hold-over may be possible... and slug BC may be massively underestimated giving us even greater potential accuracy. I'll have to try this with my Airforce Condor. Thanks Ted! :)
Hi Ted. Great video as always. Is it possible that with the change in velocity that your barrel is vibrating differently and the slugs are exiting while your muzzle is pointing higher? Sidenote: You could verify if the BC is actually increasing if you had another chronograph at your target to measure the velocity at 100 yards. Thanks!
![BOWKYLION - วิงวอน (ex-change) [Official MV]](http://i.ytimg.com/vi/cLdnZWDaO-w/mqdefault.jpg)
First of all, I want to say I am so happy to see new content on this channel. Ted is a top-notch marksman and I have enjoyed these videos for years. Regarding the BC - why not put another chronograph at 100 yards and measure that velocity compared to muzzle velocity and calculate BC that way.
Yep. Time to bite the bullet and buy a damn LabRadar.
@@TedsHoldOver teddy you have done so much for us you have a patron or donation area? Shit I’d buy your only fans if you do weekly Airguns hunts on it😂
Yes! Verry interesting to know what speed the pellet/slug has on impact, at 50 and 100m.
@@TedsHoldOver You spent over $1000 on slugs... lol
@@mikecollins8241 not just slugs, all the slugs 😂. Thats what happens when you find “The One”
I believe you found the perfect speed and twist rate for that specific lenght and weight over that specific distance. In other words, the slug flies true through the trajectory curve for perfect aerodynamic angle of attack. No nose up or down during the flight through the trajectory curve. Just perfect. The choke of the barrel will also play a big role here on how it releases that slug (angle of attack). It's like finding a needle in a haystack, possible but very rare. Good football quarterbacks have the ability to throw, release and spin the football just right to achieve perfect angle of attack, speed and twist for optimal flight in order to achieve maximum distance with the least effort. Everyone who has thrown a football enough has at some point found that "feeling" of a perfect release. This is very difficult to achieve with a barrel in a gun. I believe you have found your unicorn.
who better to explain than a slug designer.
@@XM913CG lol… great theory, but he’s incorrect
@@Oregon-airguns agree, what Rolfe is saying is kind of right but does not explain Ted results. That’s simply down to incorrect data and operator error!
The inability to find the perfect ammo for YOUR gun is what makes these air guns nothing but cash cows for the manufacturers. You are all chasing the wind! Ted got lucky....after admittingly spending OVER 1K on ammo. REDICULOUS.
The day I found my “perfect release” I started preparing a nursery.
Hi Ted, First off I'm no mathematician but you might be forgetting about the angle change when zeroing, At the lower velocity you tilt the barrel higher to compensate for the distance to zero (50yds) if the velocity increases that angle changes to hit the 50 yds zero. I put your data into the Hornady calculator, here's what it says.
1000fps, BC 0.09, 26gn projectile, scope 3.75" above the bore, 0yds= -3.8", 25yds = -0.6", 50yds = 0", 75yds =-2" 100yds =-6.9".
1100fps, BC 0.18, 26gn projectile, scope 3.75" above the bore, 0yds= -3.8", 25yds = -0.9", 50yds = 0", 75yds = -1.2" 100yds = -4.5".
1100fps, BC 0.09, 26gn projectile, scope 3.75" above the bore, 0yds= -3.8", 25yds = -0.8", 50yds = 0" , 75yds = -1.5", 100yds = -5.5.
I read somewhere that the location of the scopes reticle adjustment relative to the triangle created by the barrel and scope axis relative to the projectile start point will make a difference in the amount of clicks needed to reach zero (ATN web site I think), your rifle has the projectile a long way behind the scope reticle adjustments, in other words your adjustments are having a greater effect than if the projectile was below them
As an old high power rifle competitor, 200 to 600yds and 1000 yards. I am enjoying seeing you go thru the exact same testing to achieve the best accuracy you can from your equipment in an air rifle. Your finding that a pellet dia. in ten thousands of an inch can make such a huge difference in performance. My shooting was 50 years ago, and I heard of some top shooters that would go to the sierra factory and mic bullets coming out of the bullet making machine until the die wore down enough to get the dia they wanted and then take the next ten or twenty thousand bullets for reloading because that dia is what their barrel liked.
Thank you for the vid; it is quite stimulating --- which makes you the elite provocateur of thoughts, avvocato del diavolo, and rouser of enquiry into the logical/illogical world of Ballistics. This video shows that despite efforts to make sense of logistics with the behaviour of missiles, all pre-conception seems futile. You, sir, have dared to be the Sherlock Holmes of your vocation. "The only thing that remains constant is change," attributed to the Greek philosopher Heraclitus, seems to ring true in your efforts. To reiterate Mr. Holmes, "When one eliminates the impossible, whatever remains, however impossible, must be the truth". Thank you again your efforts. Stay well.
More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.
I think what you're seeing is your finding the sweet spot of the spin rate, ,this increased the BC which effectively increased the accuracy for longer ranges. I would almost guess the bullet as two sweet spots one low at the smaller BC and the one you have found...
I agree: it would make sense that a higher initial velocity, and greater rate of spin, would ccause more "lift" from spin "traction" as the bullet bites it's way thru the air. I love this stuff, as I've been an avid handloader for years, and the mysteries keep coming! "What we THINK we know, vs What we find in testing"
You right, if you rise your bullet speed you change its gyroscopic stabilizations. You can calculate one and check if its the main factor here
@@mikecollins8241 You, sir, are a THINKING man in the best sense. I have echoed your statements for the many years of searching for truth in all things in this world. Thank you for your maxim. Stay well.
The inability to find the perfect ammo for YOUR gun is what makes these air guns nothing but cash cows for the manufacturers. You are all chasing the wind! Ted got lucky....after admittingly spending OVER 1K on ammo. REDICULOUS.
So what about the drag increase in transonic region? At 1100 fps(about mach 0.97 drag on projectile at the muzzle is so much higher than subsonic speeds and its nothing to with spin rate or even type of the projectile (bullet,slug, airplane!....)what you saying could be true in supersonic projectiles like canterfire rifle bullets,but here we are dealing with subsonic airgun projectiles, clearly something is going on in this case,but as ted says, it must be impossible!!
Hi Ted. I just tested this with my LabRadar. I used the same barrel, 800mm 1:14 twist and same slugs, NSA 31.2gr .2165 . I shot a 15 shot string at 100yd. Average muzzle velocity was 1,087 and average velocity at 100yds was 941. Taking air temperature, station pressure, and humidity into account I got a G1 BC of .132. RA4 BC was .104.
Absolutely spot on Tyler like we have previously discussed. Absolutely no way a projectile can double its BC, it is impossible. Period!
I looked on FX's website and they don't offer an 800mm barrel in 22 cal. Who do i contact to purchase the same set up Ted has?
Hope you're doing well Ted, it always makes my day when you upload new content!
For those looking to get the .2165's, keep in mind that the performance here is specific to his setup. Each gun has it's own personality so to speak and what works incredibly well in one will not work as well in another. Replacing a worn-out barrel or regulator, etc can and will affect performance with any load.
You also need to consider lot number. For example, my M24 clone shot the first lot of Federal SMK BHTP 168 gr at an incredible 1/3 MOA. When I moved to a different lot of the same load the groups opened up to 3/4 MOA.
So, definitely consider the load(s) Ted is recommending, but YMMV.
After years on TH-cam, this is still my favorite channel. I will by an FX next year because of this guy.
It’s been 1 year. Well darn close! But you should have got your tax return by now. Soooo, how are you liking your new FX???
@@Oregon-airguns lol, I'm working on it. Finally got my air setup ready to go. Bit by bit.
@@tadracket448 let me give you some advise. Steeer clear of fx… take a look at the Vulcan 3. It’s a straight killer right out of the box. Shooting avs slugs. M channels not nearly good as teds. But I’ve been down the fx road and it was a total nightmare.
Internal ballistics are a funny thing. Barrel whip can throw the same bullet to two sweet spots at different velocities. The first (lower velocity) shot may be whipping the muzzle down slightly and giving you a stable muzzle exit at with the muzzle low. The higher velocity may be throwing your groups higher. This gives you a different number to calculate BC than the 'accurate' number. You'd have to check velocity at multiple points on the trajectory and see if the velocity is dropping with the BC.
The other alternative is that the BC is changing due to transonic interactions with your bullet profile. Bullets do weird things whey they try to push air around them at supersonic speeds, even though the bullet itself isn't supersonic. You could be getting a better BC because of the supersonic flow characteristics of this particular profile. Me, I avoid transonic as much as I can. With my .44 Magnum rifle loads, I stay at about 1,050 FPS. Bullets that fly much faster risk running into weird stuff, as you may have experienced. Only strike against this theory with your bullets is that they slow down REALLY quick to full subsonic flow.
Brilliant comment: Measure velocity drop; not POI shift.
yeah, you missed the point - he measured the difference with the same velocity 1100 at 100 and 50 and compared the difference. Pay attention, focus and don't speculate
Ted for me this has just blown my mind your dedication to education of the masses is incredible, thank you . Keep doing all that you do especially nailing the pigeons.
Outstanding shipmate. Press on. USS Kitty Hawk CV-63. Jan 1980 to July 1983. Air gunner for life.
The air bubble on/in the HP is trapped creating a "tip" on the slug. The higher the velocity the more efficient it becomes because the air bubble is under more pressure from the on coming air. This in turn lowers the resistance the actual slug is facing because of the twirling air inside the HP is under more pressure getting push through the atmosphere by the slug.
High powered rifles used for competition shooting use hpbt and not pbt rounds for this reason.
How fast is to fast before this has diminished returns? I don't know but with pcp's it doesn't matter but clearly you have just proven that this effect starts to really have benefits around 1100fps and not so much below 1000fps.
I really enjoy listening to ballistics nerds (like you and Matt) heading into the weeds of researching and explaining what's going on with slugs & pellets in flight. I'm not sure what percentage I'm missing, but it's fascinating watching you work on it.
As you get closer to the speed of sound, shock wave is formed. The slug may be drafting in the shock wave.
That's what I was gonna say but you condensed it nicely.
Wonder if the shockwave forming in front of the slug is displacing some of the air, or letting the slug ride the lower pressure air right behind it.
Also the group tightening with the increased speed can be due to barrel harmonics and (or) a reduced follow through time.
I was thinking that too, Ted hasn't responded yet though, Thanks for the content Ted, keep it up dear boy!
^^^Looks like the scammers are on the prowl.^^^
Wonderful video, I've been playing with the neilsen slugs in 21 and 23 grain in my Avenger, I upped my reg pressure about 150 psi to 2250, and I noticed a drastic difference in the amount of drop beyond 75 yards..much more so than I'd expected. Now I'm enjoying some flatter shooting, but I've yet to push them across the chrony..that's the next step 😏 thanks for another great video, appreciate your dedication to the airgun community and sharing what you learn.
I've also ran into many ballistic "mysteries" but in the end they were simply not taking into account of atmosphere conditions or user error. Temperature and altitude density have HUGE affect on BC/trajectory. Zero one day and not readjust to new weather condition into the ballistic calculation will through you off big time. I've learned the hard way and always validate zero and reset atmosphere conditions in ballistic solver with minimum local weather station information, I try use a weather meter for my ballistic solver and make a point to update the information EVERY HOUR!
Ted: Love your show and learned a ton from you especially on tuning the gun. Keep up the great work!
BC is defined by change in velocity between 50 and 100 yards. Delta in POI could be deceptive because it includes the effect of barrel harmonics.
Summary of insightful statement by RyeOnHam
nope, what he wrote was dumb because he doesn't pay attention and makes up crap that sounds smart to other people that don't understand basic math and don't pay attention. Barrel whip is not a variable because he was shooting at the same speed at 100 and 50 yards. The barrel harmonics doesn't change because of the distance you shoot or because you aim at different thing....
Received my first fx wildcat today, you posting is still the best thing thing that has happened today, Ty Ted!!
You're going to LOVE that wildcat. I grab my WC a lot more than my impact or any other rifle. It's just the perfect balance of comfort/accuracy/power. If someone were to ask what their first FX should be, I would recommend the Wildcat BT, hands down.
Great video Ted ! I’ve watched you from the start , and you got me with you never ending quest for top performance. With the right equipment, and understanding the science the hours you spend on target make it all come together .thanks for sharing your system and how it works ! I’m still amazed at shooting nickels at that distance………with air…….. !
I'd be very happy i could get a half-inch group at 50y, never seen such a group at 100 yards, Amazing!!!
I'm a little discombobulated in this one, but somewhere in the rambling there IS a point. ;)
I remember when I was a kid, my grandpa would talk to me about a “magic velocity” for his .22 cal while I sucked feverishly on a werthers original. He was a professor in physics and told me some jibberish about how at a certain velocity and twist rate, outward forces such as the effect of wind and even RAIN would have little to no effect. Those numbers I suppose, would apply to slugs from an air gun as well. Matter of fact, I know they do “;) Dam, those Werther originals are good…
@@2cthetruth this is why I come to the comments. Never would've thought of this. I need to get some werthers.
@@2cthetruth I get the 34 ounce bags from Walmart for best price per lozenge economy. 🍬
They make chewy ones now too! Just found them a couple days ago. They're very, very good.
I wonder if the air hitting the hollow point at that speed combined with entire shape of the projectile is creating some form of aerodynamic effect that is producing this.
Or maybe airflow that is hitting resistance just before transonic across its body is stabilizing it even more?
Who knows? The only thing I know is that I'm excited to see more!
High powered rifles in competitive shooting use hp rounds bc of this effect. It causes a high pressure air bubble on the tip that goes through the atmosphere more efficiently than a pointed tip does. His data is showing that somewhere above 1000fps is where this effect shines
@@adamdearien5975 that is my theory as well, I can imagine he would see decreased BC if the slug was not HP.
Rotation of the slug makes the air travel a longer distance along it. This would make the slug virtually longer. With 335m/s the slug should rotate about 20k times per minute.
Hi Ted, What you are observing is the effect the speed and hollow point has on the BC. Higher the velocity of the projectile = higher BC and the hollow point traps air (bubble) and the higher the pressure the harder the bubble is and the more it's aerodynamically shaped which results in reduced drag and higher BC.
Mythbusters "golfball effect" and "tailgate" has very nice visualization of the phenomena.
Good to see you back Ted!! On the BC is it possible that the hollow point is creating a slip stream affect like a pickup truck box does with the tailgate closed air moves freely over the truck. With the slug the cup fills with air that is compressed whether going fast or slow causing the slug to stabilize.
Probably the same concept like an arrow flying. You perfectly found the speed needed to stabilize the slug in the air. When a arrow is shot at a slow speed the fletchings need to be larger to get the same bite as the smaller fletchings at a higher speed. Like a fighter jet. They use 100% power as slow speeds because they are falling from the sky. When they actually get to optimum flying speed they stabilize. I'm pretty sure that's what you are witnessing with your slugs.
That is a great concept.
to a point but if the bow is correctly tuned the arrow will fly straight with no fletchings in other words the only thing on the shaft is a nock and a field point and no fletchings that is the correct way to tune a recurve or longbow it must be in harmony
Hi Ted, great info on the airgun and new slugs. That is pretty cool what you are getting with these slugs! I had one thought which is - why introduce the scope change into your calculation? Simply shoot at 50 yards and it impacts the target, you can make it near zero but quite honestly it does not destroy the point of aim if it hits a few inches low. Then simply back the target up, continue to shoot at the same aiming point. Measure the difference between the two groups and you have the drop at 100 yards. The aiming point is quite irrelevant so long as the aiming point is the same each distance, I actually prefer to make a cross with a heavy marker or even tape depending on what I am doing. That way no scope calibration issues are introduced, etc. The drop is what the drop is. Just have to shoot at the same point, leave the scope alone. Keep on killing those starlings!
Ted's videos are quality over quantity and once again, we appreciate it. Well worth the wait. Another GREAT video Ted!
Great info. Will definitely be trying. Thanks for sharing.
Great stuff here Ted you will find that the 1:14 twist shoots really well out at farther distances and the faster twist has a lot to do with that BC number you came up with here
Wrong!
Thank you for your videos! You have taught me so much. I loved hearing you teach the scouts, I love learning from you too
I love the Nielsen slugs in my 177cal. They work so well that I haven't tried anything else.
Good god! Your still the goat! I was like 👍 2k btw. I’ve noticed the same thing with different lots of 22lr some lots come out to .170 bc and others .123 same exact bullet, even weighed them. Billets we’re Norma Tac they vary in velocity a lot from lot to lot. Some lots 950 others 1100. Thx again Ted!
Ted,
I have encountered something similar to this shooting .216 KOs when upping the speed from (normal) 960 fps to over 1020 fps. Had to change the BC from .89 to 1.25 to get Strelok to "match up" predicted vs actual POI. Didn't make sense, so I re-checked all my input data and found that the scope height value was no longer correct(by shooting a target 10 yards away) when shooting at the higher speed. When I input the new scope height and returned to using a BC of .92, all the Strelok click info "trued up" again.
You can test if your scope height is correct or not with your new faster setup by shooting at a target that is much closer(10 or 15 yards) than your scope zero(50 yards) where BC doesn't matter that much. See if the Chairgun predicted holdover match actual POI or not.
for the BC, it could be the point of impact change because the harmonic change in different spring settings.
This is the channel that got me to buy my first large bore air rifle. I wish I could afford a higher quality one because I have a Benjamin and it's not super great or super accurate..
Nearly anyone can afford and Avenger. Get one.
What Benjamin do you have? Try Airgunnationforum as good deals are there all the time for air rifles and PCPs.
Ive watched you since the edgun matador days. The 130 yard pigeon shot got me into the air world. Ive got an impact m3 .30 cal shooting knockouts 900-905 sub moa out to 150. Jsb pellets 50.15 gr also mostly moa to 150 with some flyer. Stx standard barrel @910-915. Wish I could post pics here. Great to see the content again
What reg pressure and valve settings? Just curious, I have also found 50.15 knockout slugs to prefer 900-911 fps and 50.15 jsb pellets around 870-875.
@@nobs2767 1:165, 2:127 4+ a few click on tuner 12 on the wheel and 4 lines on the valve
Hi Ted, great to see you back, making a fantastic video and sharing your knowledge/information with us again.
I’m shooting Neilson’s (as I’ve found these the most accurate 24.8gr 217’s) out of my M3 700mm superior @ 974f/s. Zeroed at 50m, they are bang on out to 80m then start to go a little sketchy beyond that. Maybe I need to get them going a little faster?
I ran a trajectory test on the .177 JSB KnockOuts, with a posted BC of about .047 at 970 FPS. Then I fed the data into Strelok Pro. Of course using the BC provided by JSB didn’t match the real world data I’d collected, so I used the BC truing function and came up with a BC closer to .09. The shot chart in the app was within a click of my data as far out as I had data so far collected.
BC is speed dependent. Are manufacturers shooting at slower speeds? Are they using a conservative “at least this good” number? Are they calculating over longer distances which leads them to use a lower average speed in the calculation? Is Wisconsin’s dairy air magically slipperier?
Thanks for raising questions Ted!
Transonic airflow does strange things. You have found one of those things.
I am seeing exactly the same. FX Maverick 700mm, Superior liner, H&N HP 27gr .218. Claimed factory bc 0.95. @920fps I see bc of .097, when I crank them up to 1000fps bc leaps to 0.131. Used same method to verify as you did, also did verification at every 10m from 40m zero all way to 100m. Not complaining, but shocked me. Just managed to get first supply of
H&N HPII 27gr Slugs, so will need to try with them???
Amazing Ted! Would be interesting to try another barrel (the same) and see if you get the same results🤔 This would then show you have found your nirvana combination. Also cleaning the barrel to see how that affects your groups. It is amazing how far air rifle technology has come in a few years! Great video!
I cant believe how accurate your gun is, its great
Calculate the arc of flight, trajectory. Find the highest point and sight in zero at that distance. If you shoot further adjust up AND the closer you get you will need to adjust up again.
It would be interesting to try a LabRadar chrono and see what it says about the BC.
Yep. Just ordered one. OUCH at the price! :)
Set up an address on Pattoron and I’ll send you a donation
KEEP UP THE GOOD WORK
TOM
love watching you ted thank you so much for all that you do for us.
so excited everytime i see a new video of yours!
Ted's got the same problem as me, haul ass to the target and then be out of breath when I get back to the gun.
I only shoot pellets, but I still adjust my BC to get it spot on. And I have yet to find a manufacturer BC that's actually perfect. And the BC I end up with after shooting/testing a pellet is always lower than what they say!
The actual BC number is kinda weird to me because just to change the POI an inch at 100 changes the BC number a lot! But I don't really care what the number is, or how my BC compares to the one given by the manufacturer... all I care about is that it's correct for me!
Thanks for the video! I always enjoy listening to you & learning! ✌️
That was awesome, hope you continue to teach us a thing or two thanks for all your hard work.
Yes! It is possible. Getting closer to the SS - the lower is density of air flowing along the projectile. That means : less drag, more BC. A firearm bullet has his BC if the speed is above the speed of sound only.
Awesome ted!! so appreciate your contributions
Hi Ted, i know this is an old (relative post) but hers is my idea, the ballistic coefficient on some shapes of "slug" is NOT LINEAR !! as the slug approaches the speed on sound and we know the destabilisation issues of traversing the speed of sound. Drag is caused by the air stream going past the side of the pellet. The nose of the slug or pellet builds up a pressure cone in front that helps the airflow around the projectile. But it still allows the air to slide down the projectile so your changes in speed are affected by the shape and "balance" of the projectile. ( look at a Sherman tank shell when fired, its not flying straight !!! but pointed up slightly against the ballistic curve !!) but that's not the point, im just saying different projectiles act differently. ( How some pellets FLY by different shapes and C of G positions is another subject) The air stream is working with the projectile shape and affecting its coefficient as a result but in a linear fashion. Up to a point, When you are very close to the speed of sound and you were right on the edge, you are now starting to create a real shock wave and although the airstream is not creating a sharp edge that produces the destabilisation and CRACK sound, it HAS created a deflection in the airstream that has started to leave the side of the pellet.. that's where the shockwave phenomenon starts by the airflow leaving the side of the pellet, and moving forward eventually creating a hard shockwave.
This is what changes the coefficient dramatically from the predicted drag figures.. suddenly the drag drops in this small zone when the speed increases. Inversely when the speed drops around this point the drag slope changes and drag increases as the skin effect is re-established. This reverse curve is only there for a very slight variation on speed and is dependant on the profile weight and C of G of the projectile. This is why Chuck Yeager had the reverse control phenomena just as he approached the speed of sound, and had to fly through it by increasing the speed to regain control. Also affected by temperature, humidity and earth rotation etc. it's not a useable zone as the natural drop in speed over a few tens of meters will have left this variable zone.. That's why aircraft don't fly just below the speed of sound in that slightly better efficiency zone because it's so small..
Ive watched all of you videos and loved and learnt from all of them, and ive seen you shoot shell casings at the range just a little too hot where some pellets were flying dead straight and others were getting destabilised as they were affected by traversing the speed of sound. You said then that they were a little hot, and we all know the effect, but the little blip just before this critical speed is affecting the drag coefficient and upsetting your figures...just lower the speed by 10 fps and the curves will be predictable again. That's my theory, I do electronics and there is often a negative reaction in oscillations just before a positive one.
colin
Here is the response I put up on my group Precision Airgunning
So, does anybody want the answer and explanation? Its really quite simple!
Ok So, Teds theory of a .22 calibre 30 grain slug with a manufactures published BC of 0.095 having a BC of 0.180 is not only wrong, but absolutely bonkers. So lets start with some basic ballistics. Using a G1 standard BC drag models the BC is not fixed, it is in fact dynamic and changes with velocity and bracketed into velocity bounded segments. BC is normally the first thing an inexperienced user/shooter will manipulate, mainly because its the one thing that they least understand. I mean people find comfort in that they believe their velocity is 100% correct because their chronograph tells them so, we wont go into chronograph read error in this subject but just keep in mind that it does exist! A few other things to keep in mind on this sort of situation is - Range error, velocity error, environmentals, false zero and scope tracking error, to name a few, they all exist. Anyway moving onto the mysterious issue that has got all the top dogs confused! In shot ill just go out ad say it - Scope height, yes it is that simple folks an here is why. If you look firstly at Ted's Rifle set up he has a Saber Tactical back bone rail with inbuilt 20/30 MOA built in, some sort of scope base with built in adjustable elevation,, scope mounts and then the scope, just look at the scope height its crazy high. Then move over onto his Chairgun Pro data where his inputted data states that his scope height is 3.75",crazy high! Essentially what this is causing is excessive or an acute angle with regards to line of sight relevant to bore line. So some more basics, when any projectile leaves the bore regardless of velocity (500 - 4000fps for example) the projectile slows down and and begins to fall away from the line of sight (Gravity) immediately and continues to do so. So how do we hit targets at 100,200,500,1000 yards away, well we add trajectory into the equation via the scope, effectively adding ark into the equation, or lobbing bullets in laymen talk. So in order to order to hit a target at distance the projectile has to leave the barrel and leave the bore line to meet or match the line of sight, (primary (1st) or secondary (2nd) zero) With airguns, because generally they are used at closer ranges when compared to long range centre fire rifles we have to be a little more, lets call it aggressive with the angle created through our scopes in order to match our POA vs POI. This only seems to effect airguns, largely because of what I said above and their close range usage. Im sure some of you guys who shoot either sub 12ftlb air rifles, or a better example is night shooting close range rats at say 20 yards with a perfect 20 yard zero, notice how if you aim directly at a 30 - 40 yard rat you will shoot clearly over the top of it, but then a 50 -60 yard rat you can aim straight at it and hit it, this is the primary (Close) and secondary (far) zeros \I was talking about before. In Ted's situation he has come across the exact same problem but at just a further distance out, this is due to his excessively high rifle scope. To meet his 50 yard zero he will have to have some serious angle dialled to mach his POI vs POI. Once he shoots and hits his zero at 50 yards, the slug, particularly at higher speed will shoot through the line if sight and continue on its upward path above the line of sight to around 70 yards before coming back down through the line of sight back town to his distance of 100 yards. this gives the impression that the projectile is shooting flatter when it is not, its just got a greater arch due to the excessive built in scope height. I hope I have explained it in a way that it can be understood, ill add some Strelok screen shots to demonstrate that just by changing scope height can manipulate the POI down range. Ted simply has just hugely manipulated the BC value of the projectile to the point that it matched his real world DOPE - wrong on every level! I hope this clears this mystery up, just take note that we can simply explain Ted’s findings by simply matching his Correct scope hight and manipulating various scope hight settings to vary results and not BC, if you take one thing from this, make sure you pay attention to scope hight!
You can get the same results by slightly altering far zero. Also when he shot his 50 yard shot after dialing 5moa for 100, his shot at 50 is exactly 5moa high.
Another great video Ted. I have more experience of centrefire projectiles and its common for the BC to change with velocity so no surprise here. Keep up the good work !!
First let me say Ted, I love your channel/ posts, Keep it up. Thank you.
This is a great example that shows that BC is not a constant as is too often believed. This might be an example of better stability. or I will have to refer to the boys at Sierra bullets. Sorry I cant put it into words but give them a call they will explain this very well, how or why BC IS dependent on Velocity. There are computer simulations that show what the air does around a projectile in flight at differing velocities I just can not find one right now to refer you too.
BE
I think it distinctly possible that the poi shift could be attributed to a difference in barrel harmonics between the 2 power outputs. when the 1000 fps group is considered the base mark, the calculator would naturally assume that the slug maintains a higher average velocity (due to a higher bc) but, if the harmonics of the gun are altered enough then the barrel could be letting the slug out at a different angle than before (which is assumed to be 0 in both instances in your calculations). Just a thought but it could also explain why the difference between the gap in your 50 yd and 100 yd zero (from 1000 to 1100 fps) because the parabolic curve of the trajectory is such that if the two zero points were both closer to the apex of the trajectory then the change in Y (as it were) would naturally be less. Tell me if I'm off the mark with that though
Ok, got it figured out i think. If you punch in a 58yrd far zero in chairgun, it puts you .15in high at 50. Close enough right? But it then kicks you up to less than 5in drop at 100, without messing with the bc at all.
The .216 is amazing in my Liberty and my Avenger. The .2165 isn’t to bad either but not as good in a Nova Vista barrel. Really happy around 900-940 with 20.1 grain. That said they my not like another barrel from the same company. Pays to buy variety when testing👍💯. All that aside I believe what your experiencing has to do with twist rate, sectional density, and speed. A slower twist rate and lower velocity will produce more drag if I have my head wrapped around this right. Hopefully you will do a follow up video on this.
Always a pleasant surprise when you post a new one. Good stuff.
Chris Turek did some groups at around 1200 fps. He had some pretty good success I thought. There is potential for airguns to operate at supersonic speeds. I get that the whole point of air is to keep it quiet, but I'm absolutely sick of everyone defaulting to "you can't shoot air projectiles over 1000 fps, it won't work". That's a pile of malarkey. I truly believe you can and it's going to become a lot more normal one day.
To be clear I'm not saying you can just launch things out there at 1400 fps. I think you need several things in harmony to still maintain good grouping / accuracy / precision. Most important being twist rate.
What's perfect for 100 yards may not be perfect for 40 or 50 though. Everything is a trade off.
Either way, keep pushing the envelope Ed. You're work is, and always has been quite important and we appreciate you.
Interesting. Before searching for a reason for which your calculated BC has almost doubled, maybe its worth: trying another rangefinder / another chronograph / confirming your results at 200y (you would probably get a lower than double BC) / trying to shoot without the moderator. Or maybe the change in rifle harmonics is moving the barrel up when pellet exits the gun, not very noticeable change in zero at 50y but more pronounced shift of poi at 100y ? Great video though.
I agree with some of the other comments... at 1000 ft/sec the slug might not be fully stabilized and thus is wobbling slightly with increased drag, thus the lower BC. The additional RPM given by the extra 10% of velocity is fully stabilizing the slug, hence the lower drag and higher BC. Interesting though, that a standard .22 LR 40gr bullet is expected to be fired through a 1:16" twist barrel and to be stabilized. I wonder if this is too low, and if we might see more accuracy from .22s with 1:14" or even 1:12" twist barrels.
we hope to see the white glasses back 😎😎🔥🔥 I'm happy to see the legend back
Try a harmonic stablizer, move it up and down the barrel and see if you get a change in grouping. That would rule out that variable if you dont see a drastic change in grouping.
Some good comments here!! Another thought I had Ted, speaking from an engineer's standpoint, is to confirm your data to make sure nothing is lying to you.
Specifically in this case, would it be worth calculating the BC based on Vo (initial muzzle velocity) and V1 (velocity measured at impact)? Unless I missed it, you're currently only measuring one velocity (I assume muzzle, since I'm not 100% familiar with your equipment), and we don't know what the other velocity is (in this case I assume at the target). Maybe your app works such that it's measuring the delta in sound from gun firing to impact, in which case it's inherently measuring only one velocity.
Although it's a bit risky (shooting your chrony), I've placed mine at the target in the past after knowing muzzle velocity, so I can then measure target velocity and confirm manufacturer's claimed BC. Anyway, just a thought to ensure your data! 🤙 As we say in engineering, garbage in garbage out! 😜
Hi Ted. You're the man broseph. Come on out to new Hampshire and we'll rip up some grey squirrels. I love all your videos I love how you get in depth and explain all the math in a way that's made simple. Keep up all your good work and keep up all the videos Ted. You are the balls and I always look forward to your next video. Let me know if you are ever in New England we can tear it up
BC is comprised of a bullets sectional density and its form factor. Form factor describes the drag of the bullet in comparison to a standard. The old G1 standard is not representative of modern bullets in terms of how its drag changes with speed.
So, as velocity increases, the drag of modern bullets is lower than the standard, so the form factor decreases at higher speeds, which means the BC increases.
Hi Ted , really great and interesting video, with that BC confirmed at 100 yards and add to the fact that the slugs are shooting 100 plus fps faster than what Nielsens do at say 1000fps I think it would be safe to say that you are flattening out the trajectory or ballistic curve , so then enter your average speed into something like strelok shoot at say 200 yards or even at 250y which ever you feel comfortable with but it has to be quite a bit further than 100 yards and see where strelok tells you to dial for say 200 or as far as you are willing to shoot and see if the ballistics match up , the reason I say this is because if 100 yards is the longest distance you are going to shoot then that’s great but like most of us we all like to test ourselves to hit things further away whether that’s cans of pop golf balls or hunting you will need to see how that BC matches up to your turrets at further distances , sorry if this is a boring long ass comment lol but I would like to hear your thoughts on it , all the best G.
Can I lend you a period? Here’s a few……
Great video Ted, thank youvery much for all the useful info, and data
Thank you. Yours is the information I trust the most and look forward to each installment. My M3 factory 700mm shoots pellets great but is giving me fits with slugs. Not sure where to start. 22cal.
Twist rate is to slow with factory liner for slugs.
Barrel harmonics and actual sight height above boreline, perfect spin rate for optimal BC and finally the transonic airflow to the rear of the projectile should be considered.
its possible, and a known occurance with certain shaped projectiles. considering g7 drag model and how its averaged over mach 1.75, 2.0, and 2.25. doppler tracking projectiles brought light into this stuff.
always a good day when we get a new Ted video
I will up my speed and try to replicate what you have done here. Great video!
I am bumblebeezed by this video
Great video Thanks for all the hard work, you making me want to purchase the FX and putting away my Hatsun Gladius. 25
Great job Ted, love what you do here.
Mystery for sure, but your bumble BC math looks right. Love it. Thanks. Jess
Good lord is right.. That disappearing head trick was amazing 👏
nice to see you again after years
First thought (layman speculation) is that it's related to being transonic; maybe see if the bc is still as high when calculated between 100 yds and 150 or 200 yds after the slug has slowed down a bit.
Haha ha hahaha ha….you said trans 🥴
That's my guess too. It's really close to going super sonic (maybe closer than he thinks because of atmospheric conditions) so there's a pressure wave or whatever in front of it, displacing air.
Bryan litz just started testing airgun projectiles. I’d shoot him an email. There is literally nobody on the planet more knowledgeable than him on this subject.
Agreed.
Hi Ted, spoke to you the other day about your finding but the comments appear to have been removed. Ive listed them in my group Precision Airgunning if you wanna take a look.
This the guy who got me into air guns
I had Igor add the G8 BC to StrelokPro a while back because I had found the G1 and RA4 wouldn’t match but the G8 with the neilson stuff was spot on
Yay keep the vids coming been watching since the beginning. Maybe have a question what do you think about the fx dreamline power pup. Been looking into it and wondering if .22 or .25 which would be better for shooting a combination of slugs and pellets
Hmm, seems yt didn't post my comment because I linked to a paper. (Estimating Transonic Drag)
In any case, here's a clip from their abstract which should explain what you are seeing.
"For the most part, the drag coefficient (which is dependent on the local Mach number) is well-understood for subsonic and supersonic velocities. However, there is often a rapid and unintuitive change in the drag behaviour near the speed of sound."
always count on ted to give the best info. Fully agree on the .2165, works amazing even on the 700mm with the heavy liner
I think in order to figure out what's going on with the bc you need to have more data. At very least have final velocity at 100 yards. It could be that as speed increases, the spin also increases making the slug more stable. If there's even a little bit of weeble wobble it will have to push through more air during it's flight even though it's traveling an equal distance.
Putting it simply, the G1 reference drag law is not suitable for slugs with a large meplat, particularly at speeds over 1000ft/sec, and measuring drop should never be used for calculating BC as it is the most inaccurate method. Your results are basically showing up the large problems with still using the BC system for calculating pellet and slug trajectories. You don't need any theories about shockwaves and spin rates to explain it.
I did write a much more complete explanation, but it seems to have disappeared.
If you ever want to do either a DOE or some MULTI variable analysis reach out.
Cant input with your slug info as I've got a wolverine 2B hi-lite that doesn't shoot slugs well (Or i haven't found one yet, just bought 216 JSB not tested yet).
In the video you said that MOA is about 1" at 100yds, (1.047") I've got a Helix and Titan ( Bought from Giles airgun 101 in the U.K. awesome scopes.) mine are in in Mrad but I'm surprised that Element didn't use SMOA in their MOA models to help with the maths, is there any reason why they wouldn't have gone with the 1 click is 0.25" SMOA @ 100yds.
Love it when Ted is buzzing about things again.
Ted the legend that is. All the best Wales U.K.
With all the money you have invested in that setup wouldn't it just be cheaper to call in an air strike on the pigeons? Great videos by the way..
😆😆🤣
My sides.
This is why the smartest guys on the range are the wind coaches!
Take the new bc and test it out at distance. 200 or 300 yards. See if the ballistic calculation lines up with using the new bc. Mathematically it would make sense that the bc has changed because it isn't impacting where the .09 is predicting. Which would make sense if the bc of the slugs is based off of 1000fps testing.
Great to see you back Ted!
I don't know what's happening either... but I like it. ;) What it means to me is that shooting slugs 200+ yds without massive hold-over may be possible... and slug BC may be massively underestimated giving us even greater potential accuracy. I'll have to try this with my Airforce Condor. Thanks Ted! :)
Hi Ted. Great video as always.
Is it possible that with the change in velocity that your barrel is vibrating differently and the slugs are exiting while your muzzle is pointing higher?
Sidenote: You could verify if the BC is actually increasing if you had another chronograph at your target to measure the velocity at 100 yards.
Thanks!
What I took away from moving near the speed of sound when I was in school was throw all your normal assumptions out the window.