Ep. 057 - One Hole Groups? | Dispersion |
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- เผยแพร่เมื่อ 22 ธ.ค. 2024
- On This episode, Seth is joined by Senior Ballistician, Jayden Quinlan. In recent episodes, we've covered using statistically valid sample sizes to determine rifle and shooter capability. This episode expands on that, and tries to answer questions like, "why don't all bullets go into a one hole group?" and "what are the factors that cause group dispersion?". Many of the things that influence where a bullet goes are misunderstood and this podcast explores those factors.
Another exceptional podcast, Gentlemen. I particularly like the fact that two experts in their field do not talk down to us, the listening public. You give us the technical and scientific terms and how it all fits together, and yet do not alienate the casual listener, nor the person who is starting out on this fascinating journey.
Kudos, Gents. Keep these coming.
PS. Perhaps a bibliography/reference section in the description would save those of us who are very interested from scrolling through the transcript, and trying to decipher the automated transcription…
This is the second or third time I've listened and it's still very helpful. It's amazing how easy it is to be wrong about what's causing dispersion and variability. Listening to Jaden give basic descriptions of these things clears out a lot of fog.
This is fantastic. Without this, there is no other way that I would get to hear things like this that truly deepen my understanding. Dumbed down enough for non-specialists like me, but not so much that the idea behind the issues are completely glossed over.
We intellectually know that there are imperfections in manufacturing, but this presentation gives us a much greater understanding of what those problems are and their effects. That, in turn, gives us the knowledge to make more informed choices in rifle purchases or builds, reloading components and equipment, and reloading practices. I have saved this video for reference and will watch it again and again as well as using directing fellow hand loaders to this excellent source. Thanks for the education!
Thanks for watching and the thoughtful comment!
Love the podcast and loved when Jayden went on Erik cortina’s podcast
That was the greatest episode. Both of them are amazing!
You have a lot to learn then Erik is a smart man that can teach you a lot
I have a savage 17hmr with a stainless heavy barrel did some work to the stock and it puts round after round in damn near the same hole at 100 yards with hornady 17 grain ammo until the wind starts blowing. Probably my favorite bolt gun.
These podcasts get a little bit crazy technical at times, for me anyway, but I am used to that sort of thing. It's like when having coffee with my two old buddies who are structural engineers and they get into a discussion on statics and fluid dynamics. Keep throwing the heavy stuff in our direction. It's all good.
Excellent.
Wonderful to hear the reality of the situation instead of hearsay, opinion & basically everything which can be covered by "IT WORKS FOR ME".
Great Job Jayden. Keep it up, the shooting world sorely needs it.
Thank you!
I like the visual aids. Please don't let the lowest denominator determine the quality of your productions.
At 35:50 Jayden refers to the fact that faster bullets exit the barrel sooner than the slower bullets and the barrel is in motion so they exit the muzzle at varying times so the muzzle is pointed in slightly varying directions with each bullet. I would be very curious to hear Jayden’s opinions/discussion on the topic of positive compensation which is a hypothesis studied by Tim Sellars that proposes that the muzzle oscillates up and down and if you time the bullets to exit the barrel while it is in the upward direction of oscillation, the faster bullets exit when the barrel is pointed lower and the slower bullets exit when pointed higher resulting in the faster and slower bullets tracing separate trajectories that will cross paths down range resulting in less vertical dispersion down range than you would predict via the application of the simple cone of fire model of dispersion. At 36:40 I think he is referring to it as cross velocity? and choosing to leave it aside.
When you guys come on, my attention and listening is riveted to the screen, as these podcasts are just so informative and digestible, unlike anything that’s really come or been available before. Look forward to more.
Thank you! 🙏
Man I loved this conversation. As I have often said you can only control the variables while the bullet is on the bench being made once it leaves that barrel it’s up distance, air density, wind speed across your shooting plane (over distance you can have multiple winds in multiple directions), humidity and lastly temperature of the environment and temperature of your barrel. In the end all we can do is fix each step in our process one at a time by learning from our mistakes and if we are smart the mistakes of others and whittle them down one at a time overtime. I agree with you on just about everything you have said and I don’t think anyone could argue it’s all about tightening up of your variables of cause and effect to achieve the desired result. Finally choose a good projectile manufacturer who cares to make an accurate bullet not just a profitable one. Thx Hornady
Wow, this a great discussion! One of the first times I don’t really have any questions nor criticizing comments afterwards l. My wheels are just kinda spinning. Great job guys Thanks
Very good presentation of the factors the can cause bullet dispersion up to the point where the bullet leaves the barrel. I hope you are planning another presentation on the factors that contribute to bullet dispersion as it travels from the muzzle to the target.
I had refused to watch this video because of the title. Glad these guys mentioned this video in a more recent video.
Without a doubt, one of the best discussions I've had the pleasure to listen to. Thank you, guys!
Glad you enjoyed it!
@@hornadyFascinating details.
Thanks for another fantastic session. Loving these ballistic podcasts
Glad you like them!
So many variables to precision shooting,bullets,barrels,scopes,shooting form,ect…Good talk Hornady👍
Question for Jayden please.
When you drilled the CX and marked and loaded them 12,3,6,9 o‘clock did you notice that the groups were placed at a 90° delay ?
Greetings from Germany
Torsten
Thanx for all the great info,so longer the barrel more moving,so is that saying a shorter barrels moves less ,hence more accurate?
Thank you gentleman These things have been great thank you guys
Glad you like them!
Very informative. Many questions I have were answered. Great job,keep these podcasts coming.
Thanks, will do!
So if a faster twist rate exaserbates existing variable problems, but you have to have a fast twist to stabalize ie. 22 arc, how is that cartridge so inherintley accurate?
Going to have to listen to this one more than once, lot of information and a lot of processing involved. love the idea of a reading list hope you can make a list for us
Glad you enjoyed it!
So many variables involved.
Question:
Variables we can eliminate would be the scope of my question.
Bullet Jump. I am a novice reloader, but if I press the bullet into the cartridge leaving 10 thousandths of an inch between the ojive and the lands, that reduces bullet tilt quite a bit, right? But in your podcast your saying moving the bullet so far foward leaves more empty space in the shell.
It's a trade off, however, after measuring how far i've moved the bullet forward, I should be able to then add more powder to the shell to fill the increased hollow volume within the brass.
Right?
If I add powder, how to be safe? Slower, or faster burning powder?
Thank you.
Love the podcasts and I also went down the path of OCW etc adopting the various methodologies out there, which ultimately led to a an optimized" recipe based on charge weight in response to compensating for barrel vibration. Watch a couple of the podcast on topic of "cone of dispersion" and large sample sizes required to characterize it. My question is "does this cone of dispersion change with either length of barrel or charge weight? Is there a unique (dispersion minimized) pressure (muzzle velocity) vs. barrel length, assuming all else are constant? Simply put, what is the best way to minimize the cone of dispersion of a rifle, given ability to change variables and ammo components. it seem the typical fine tune knobs such as seating depth and COAL don't move the needle much or any based on large sample size testing your guys have performed. Great work and podcast, btw.
Thanks for the pod cast.
Our pleasure!
Prior to 26.53 you mentioned material being pulled off the end. This would lead me to believe. That I should never shoot a threaded barrel without the thread protector on it. The protector protects the threads but also the end barrel crown from expanding as it replaced the removed material.
Am I correct?
With the bullet trying to throw itself out of the barrel, would that cause more barrel wear on one side or another??? I see this like bowling with your kids, and the bumpers are up, and the bowling ball is bouncing off as it goes down the lane as it hits the bumper harder at the contact point causing more wear at that point. Any thoughts @Jayden Quinlan @Hornady Manufacturing.
Great information, the most time I have ever spent listening about ballistics. Nice to know it's not my fault, well that is if I do my part the best I can everytime.
Well said!
Seth your than man! Keep up the great work!
I appreciate that!
I’ve shot poorly quickly cast heavy subs from a ak and it’s obvious when their really offset they make a cool whirling noise as they go down range. They still ring steel though and are accurate enough. But obviously if not spinning they would fly off as a bad flyer. Which they are a slight flier but otherwise much worse.
Great video guys, i listen to yall and follow your advice always!!
I'm a reloading enthusiast and I've been doing this for accuracy only with plain Jane hunting rifles. Every single rifle that I have will poke a single jagged hole everytime I do my part right. I will say that the newest rifles have very tight chambers and better barrels that are inherently easier to work with. My old 700 BDL in 30/06 and 257 Weatherby are very accurate for the older ones, and the 308 Ruger American and the 243 Howa model 1500 are the newer ones that have the tightly constructed chambers. All will do the trick when reloaded, but the Howa will do it with factory ammunition. My congratulations to All the folk at Hornady for making the best ammo agoin. One thing that I always do is let the gun cool for ten minutes between shots. This gives these # 2 contour barrels time to retract from the heat.
Love these podcasts! Keep it up!
Glad you like them!
Good day..Im curious as to what year were you guys starting to use the AMP jackets in the .224 40gr vmax?..thanx
That “bugle” area gauging the barrel with pins that caused dispersion of the bullet.. l remember slugging barrels, military barrels primarily, getting the loose and tight spots. But my sporting rifles are tight from throat to muzzle exit when running brushes or patches.
Do we know if a bullet can stabilize after leaving the barrel canted better with different shapes/ogives/tail in a reasonable distance to target much like an arrow can with proper drag/helical fletching? In other words , does a bullet stay in a wobble indefinitely. It's easy to use paper to see keyholing with arrows but nearly impossible with bullets unless the bullet is in an actual tumble state. If the bullet can stabilize in a reasonable practical distance, how far off random course will it be by bullet stabilization? I'm assuming this would be a strong argument if true for flyers outside user error.
Really love this info. But what about how we can apply this info?? What can i do with my rifle to affect this? What should i look for in a rifle when buying/building a new rifle?
Very much depends on your use case and how much you want to throw at it. My take away is once you get to 0.5MOA other factors are a much bigger deal. Shooter skill, environmentals, component quality and skill assembling them.
Really interesting gentleman. It is amazing gunsmiths/manufacturers are able to reduce these variables as much as they have. Keep up the great work!
You can’t realistically apply this information in the field because you don’t have a way to quantify the information that you see on target and what caused the bullet to do what. A cloud passing in front of the sun causes an air density change. Can you measure the difference that made and do you know for sure that was the cause of dispersion or was it something else?
How far into the weeds do you really want to get?
You will literally drive yourself mad trying to apply things that can only really be measured with rail guns in controlled environments using tens of thousands of dollars in equipment, it’s just not worth it in the end.
i love all the knowledge being shared, really enjoy it. one question what is the beste steps to go in like '' i got my new gun how to get the most out of it"? do you start reloading from round 1 with beginner knowledge or start with factory ammo and learn you rifle? again thx all the way from belguim for the knowledge.
I’d get around 100 rounds through it before starting to reload. The barrel will speed up and change the node
Could you manufacture bullets with controlled offset and a marker so you could orient all bullets to 9 o clock, so they would impact at 12 o clock?
At 42.28. So an even break around the break would create a more even escape and not throwing it off.
So rather that run an uneven break run an even break or no break?
Once again, it's great to hear from Jaiden Q's knowledge bank. I would love to hear him break down another ballistic factor that he has missed so far in the podcasts; Facial-ballistics. It's too complicated to explain in a text, but it has 2 components that work together (look closely at this)
1) "BANG !!!"
and
2) "👍😁👍"
🙂🙂
Enjoyable pod. Makes sense to me.
Possible future Podcast, "Travel of bullet trajectory." Can a lay person like me work it out? Are there calculators that work it out? What ballistic stresses & external factors impact the path of the bullet. Thanks!
Hugo Dale from Northern Ireland!
Great vid.
Close range M4 guys may want a different break for dirt and dust flair up.
Long range guys want pin point so different break.
Great data.
It pisses me off that SDI won’t let me take only the ballistics class without the entire gunsmith class.
I want to learn he ballistics side.
Crazy that I hated school in HS but now I can’t learn enough.
Could there also be gas vectoring as the bullet leaves the end of the barrel? When you see slow motion of the bullet exiting, it is preceded by gasses.
I picked one bullet manufacturer and design and velocity and have been using it with the Harrell barrel tuner and it performs exceptionally ! If I change any one of those things it requires a retune.
The gun requires attention to details for it to perform at its best! I wish manufacturers would make a true boattail bullet for top notch 22lr competition. Im trying to group out to 1000 yds.
I have been bitten by the 7 mm PRC bug and I will have a unit ready in a few days. Plus other accoutrement. And I bought 100 rounds on GB at about 3.5 per round. So now I am looking into seriously hand loading and reloading now, to see if I can save money. And this is a lot of good information.
One if the things I read is that if you can monitor and keep a small tolerance for bullet weight, and the powder charge weight, that will help.
As they say u won’t save $ but you’ll shoot more. But it’s fun I like reloading more than possibly more then shooting or riding motorcycle .
@@jefferyboring4410I just now saw this reply. True. At this time, I don't have as much time. However, I am getting good results with the factory ammo. And it is becoming more available. Federal has come out with a 7 PRC 175 ELD-X style bullet.
As the bullet and the interior diameter of the barrel heat up, even with the first shot, the gas containment improves which increases pressure and faster burning of power?
Thanks for the suggested book list. Great talk.
Any time!
One shooting podcast to rule them all.
It's amazing we can achieve any level of precision!
There are manufacturing technologies, such as those used in semiconductor manufacturing, that can eliminate offset CG issues in bi-metal bullets.
The bottom-line is consistency in all aspects of shooting is key to one hole groups: Rifle, ammunition, shooter relationship to gun and ground, sight alignment, trigger control, and wind and weather condition. Once, in a long range practice session with optic at 1000 yards prone sling supported position I shot a pinwheel X followed by three shots which broke the spotting disc spindle. That was some kind of record for sure but at the time I only thought my 6.5/284 was pretty well zeroed for conditions. The other thing for sure is I had a princess and the pea sensitivity for my NPA, as well as some really magnificent ammunition which I handloaded to perfection. Later in day, I had a bullet rip in flight snd then upon inspection of remaining rounds I discovered thin copper wrap on some bullets. At any rate, the session was great prep for my next match 531 in 2003 National Long Range Championships, an iron sight 600 yard prone event, where I finished with a 200 clean and 14 X’s. Not good enough to win but I was still happy and learned not to go for record fire from a cold barrel.
Boots Obermeyer once told me that anything you go to the outside of a barrel would also change the inside of the barrel. Then, later on he was turning the outside of a barrel and said this little bit won’t matter. I had really good luck with his barrels. Some people preferred other makers. He is gone now.😢
Every Obermeyer barrel we ever chambered was exceptional. I wish I had a hundred of them in stock today.
Rate of twist would vary with bullet shape ie round ball to conical in black powder guns.and also case neck could cause the PAT if neck doesn't open to release bullet on one spot it would cause drag and tip bullet to one side or the other. Good video! So many things can cause bullet grouping size.
would have liked to hear you discuss barrel tuners in this conversation.
The bullet finding center of the bore increases accuracy along with controlled repeatable head spaced cases with the shoulder being concentric to the chamber consistently repeats the bullet being centered.
What book is he talking about around 9:50?
Blackburn Defense channel had a very interesting video about how this dispersion makes small sample groups worthless in determining a better reloading recipe.
I saw Jayden at SHOT show and didn’t even have to corner him in an elevator. 😂
We had a very pleasant conversation as a matter of fact.
Keep up the good work guys.
Thanks Erik!
Great info here. How about a "Pareto Chart" on all the variables, i.e. which of all the ones are the most important and have the greatest effect on accuracy/dispersion?
I had a serious asemetric bullet issue about 17 year ago…was reloading and got a new batch of sst style 165ish grain 30 cal in a 300 win mag if mem serves correct 81gr of powder somewhere around 3300 fps …the rifle had always been accurate ……I could not get it to group I fought it for weeks …until I noticed (by accident) when I spilled the bullets on my glass table the tips wiggled …went back to my few remaining bullets from a previous batch she drove tacks again
As a non reloader, I wonder how much changing the seating depth of factory bullets with a bullet puller and a reloading die could improve accuracy for an individual rifle?
Question: If a bullet's CG is off and it "wobbles" down the barrel and in flight, doesn't the wobble distribute itself evenly cuz the bullet is spinning and the off-center CG cancels itself out due to the spin?
If you understand centrifugal force, you see why there isn't a cancelation of bullet wobble
@@lenniephillips9747 Apparently, I don't understand centrifugal force. In a spinning object, wherein the lopsided side of a spinning object spends an equal amount of time at any positional degree around its axis, why isn't the centrifugal force distributed more or less equally around 360° of rotation?
@@sixfiveoutfitters1201 as soon as the bullet leaves the muzzle, the offset of the CG will continue to grow away from the centerline of the bore,13:54
@@lenniephillips9747 OK, makes perfect sense; I missed the obvious. While the wobble might be distributed equally, it causes the bullet to wobble in wider and wider equally distributed circles.
It wabbles in a cone or tube shaped line and as the bullet slows it lessens. As some who has cast extremely offset heavy subs it becomes obvious as u can hear the effect and see the patterns they make. They still hold a certain size group say 4” or whatever but absolutely will not group less than that as every round will be spinning in it’s own circle ⭕️
After all this tech talk,and could be problems..... I'm glad I can just hit the Broadside of the Barn;).
Very interesting pod cast!
Glad you enjoyed it
I was watching a video from Brandon Herrera and he shot a .50 cal with a high speed camera. It was really interesting to see just how much the barrel shuck or waved. I never would have thought about that before seeing that video. I think it was his AK-50 video. It was very cool to see and if you haven't seen it I recommend checking it out. I'm pretty sure it was fairly recent.
Great presentation! Thanks gentlemen.
Glad you enjoyed it!
Owning two lathes with 30+ chamber reamers, i found that barrel quality of uniformity, with best harmonics thats stress relieved, with the proper testes load! that you must search seek and find! Are the two biggest factors that affect mechanical accuracy and firearms precision facts! Inaccuracy is bullet prosession,bullet nutation, bullet Yaw, simple way of explaining it is a perfect gun would be a bullet flying and spinning like a drill bit spinning not a spinning drillbit that is corksrewing at the same time!
Are there bullet manufacturing processes that can lead to more of a center of gravity offset? More so with the bonding process. My theory is that with the energy for the copper and lead to bond, the copper can flow more into the lead as an intersticial (probably spelled that wrong) atom and cause a more likelyhood of the center of gravity being offset even more so than a non-bonded equivalent.
A bonded bullet process does not magnify a jacket that is non-concentric.. the swaging process can cause non-consentric jackets.
A all copper bullet, or all the same material, is concentric, and less able to induce a imbalance caused by not being concentric.
This makes the one hole outside 1/2inch hole from my 22-250 on the first handhold was like winning the lottery. 100 yard, 5 mph wind, mid 70s ,afternoon sun. Checked length of throat and set jump at about 15 thousandths. It was a Hornady 50 grain spx(I think). The group could just about be covered by a pencil eraser, so I loaded 200 and introduced many guys and gals to accuracy.
So this guy takes information that is way over my head and dumbs it down so I get it
Someone should tell the benchrest guys, they're still trying for one hole 😉
Jack Neary 5 shots at 200 yards 0.110 inch. He needs to do better. 🤣
And they get one hole.
@@jasoneverett7343 Almost...😉
@@tallyman15 There's one hole and then there's a one calibre wide hole 😉
What's really mind blowing...There are archers that can outshoot some rifles...A bows string has more variables than a rifle...barrel...Most issues are the shooter and ammo selection
You don’t want to go shorter and stiffer for the barrel, at least, not to the extreme, for another reason you didn’t mention. You do not want an infinitely stiff barrel. Not unless you can also have ammo that has zero velocity variation. An infinitely stiff barrel makes you a slave to muzzle velocity. You will see elevation on target directly related to muzzle velocity. Faster rounds will hit higher and slower rounds will hit lower. Which brings up another topic you haven’t yet covered: positive compensation. You need the barrel to move. Manipulate things so that your barrel is swinging upwards at the moment the bullet exits the muzzle and swinging at a favourable rate and you’ll change the departure angle enough to compensate for velocity differences. In a target shooting sport with a known and fixed target distance you can use this to your advantage to dial out as much vertical as you can. This can fight against you if you have a random target distance, but you can make it work for you at a distance that’s known ahead of time. Such as a benchrest match.
You can design a barrel and barrel contour such that it will be moving upwards at time of muzzle exit at a rate faster than ideal. And then you can use a barrel tuner to slow it down to closer to the ideal rate and fine tune it with the tuner settings to get it as close as you possibly can to the ideal rate. For a known target distance you will have a rate that will compensate for velocity differences so that it is pointing at the required angle to hit zero in the elevation axis for whatever velocity that bullet is leaving. There are constraints. You do have a certain amount of velocity difference, a certain range, where this will work. It stops working as soon as the barrel changes direction again. So you dial everything in so that you do the best you can to ensure that all your shots leave during that upswing. I think this may be easier to accomplish in the rimfire world versus the centrefire world, but it is possible for both. I believe for 50-yard benchrest, which is a rimfire thing, the desired rate is something like 6 MOA per millisecond. If you can get your barrel swinging upwards at that rate during the muzzle exit window then it will compensate for velocity differences at that target distance, removing all vertical that comes from velocity differences. Naturally, this is not the only variable. So you can still have vertical from those other variables that still exist. But reaching this state will remove as much of that vertical as possible that comes from velocity differences.
Eley lists the average velocity that a given lot of their 22 LR shot from their four test barrels. This allows you to easily select two lots that have differing average velocities. And, of course, you can use a chronograph to monitor and confirm this velocity differences between those two lots. Taking the slowest lot you can find and the fastest lot you can find makes it very easy to dial in such a tuner system. Shooting groups with each lot separately will give you targets that show different points of impact. The fast lot and the slow lot will exhibit a vertical delta. And you can exploit this to dial in your tuner. First you need a barrel contour that swings upwards a bit too fast. And then a tuner of the correct amount of mass to slow that barrel down into the correct neighbourhood of swing rate.
A barrel that is swinging just a bit too fast will show the fast lot printing lower on target than the slow lot. Yes, the faster velocity lot will hit lower on paper. Shouldn’t it hit higher because of the higher velocity? With an infinitely stiff barrel, yes. But not with a barrel that moves. With a barrel that moves, and more specifically, with a barrel that is swinging upwards at time of exit just a little faster than the ideal, faster shots will hit lower because they spend less time in the barrel. Slower shots will hit higher because they allow more time for the barrel to swing upwards because they're in the barrel for a longer amount of time. So when you have a good sample size of the fast lot hitting lower on paper than a good sample size of the slow lot then you know the barrel contour is suitable. Then the next job is to figure out how much tuner mass needs to be added to slow it down just enough to approach the ideal. As you add mass the groups from the fast lot will rise on paper and the groups from the slow lot will fall on paper so that the two lots begin approaching the same elevation. As you continue added mass you’ll reach a crossover point where adding more mass then makes the fast lot hit higher than the slow lot. So your tuner mass needs to be just shy of what makes those two lots meet on paper. When it is just shy of that mark then the tuner adjustment let’s you creep up to just the right amount. Turning the tuner outward moves that outer portion of its body outward. Moving that mass outward slows the upswing down just like adding total mass slows it down. So you’ve got a tuner mass that’s really close to what you need, and then the tuner’s adjustment allows you to dial it in to just the right amount. You can indeed get an ammo lot with an average velocity of 1055 to hit the same elevation as a lot with an average velocity of 1070 by doing so. All the other variables still exist, but elevation due to velocity is one you can deal with in a relatively easy manner.
Everything is a compromise. Different barrel contours are not without consequences. The requirements of a hunting gun that’ll be shot at random distances are quite different from the requirements of a benchrest gun that will only ever be shot at one known distance. The hunting gun will have to do well, within reason, at any random distance. But a single-distance benchrest gun is a situation that allows tweaking of many small details in order to tailor it to do a better job at just that one distance. This allows you to find a contour that works better. This allows you to find a given contour that works well with a given tuner. But you’re then more restricted as to the conditions under which the gun will perform its best. A gun fine tuned to as close to perfection as possible for a 50-yard target will perform worse at 100 yards. This is unavoidable. Simple ballistics will confirm that a contour-tuner combination that is set to dial out as much vertical as possible at 50 yards is actually introducing more vertical at 100 yards. You could set it up to dial out as much vertical as possible at 100 yards, but this too would mean introducing more vertical at 50 yards. Getting two projectiles with different velocities to hit the same elevation at the same distance requires altering their departure angles. You can set the departure angles so that they both hit the same elevation at 50 yards. But take those two different departure angles for those two different velocities and look at what happens with them when shot at a 100-yard target and you’ll see that there will be an elevation delta even though at the 50-yard mark that delta is zero. The difference in departure angles required for two different shots with different velocities is tied specifically to the target distance. You can dial them in for one target distance, but this means by definition they will be incorrect for a different target distance and you will have vertical at the other target distance. That’s just how things work. The other distance will require a different departure angle delta. You can compromise and have a gun that shoots acceptably well at a lot of distances or you can have a gun that shoots remarkably well at one distance. Really, they’re not different cases. It is just that in the latter case you’re going to extremes to tailor its performance for that one distance because you only care about that one distance.
And some people try to control barrel swing or whip with a tuner donut.
More truth here than most realize......different contours matter.
@@quarterminutemagnums If you go to the Varmint Al website he has a page called 22LR Rifle & Tuner. Just past halfway down that page he has an idea for a contour he calls the two-flats contour. He compares its theoretical behaviour against that of a reverse contour barrel that used to be popular in the rimfire benchrest world. His two-flats contour shows nearly ideal positive compensation for 50 yards without a tuner, with a calculated vertical dispersion of what looks to be just 0.035-0.04” in his graph example, and he suggested that the tuner it would need would probably be very light. I had such a barrel built. It works fairly well without a tuner. I am currently in the process of figuring out just how light of a tuner it needs. So far, it seems this is probably going to be very light indeed. I started investigating between 75 and 89 grams, but even this appears to be too much. Next I’ll start testing from 25 grams and up. So far I’ve shot ARA scores in the range of 2100-2300 with it, which are decent but not great, and I suspect there’s more to be had even just from testing with better ammo and finding what a lot it likes, in addition to more tuner testing. I’m looking forward to testing between 25 and 75 grams. While I was beginning testing with the 75 gram test tuner i shot a bunch of groups ranging from 75 grams to 97 grams before I went about measuring the results. Just going off a visual inspection I thought the 89 gram example looked best so I shot an ARA target without the tuner and with the 89 gram one. Once I got to examine all the data I was surprised to see all the tuner weights tested shot worse, including the one I thought looked best to my eye. I looked at Al’s graph some more and I figure it probably needs even less weight, judging by how far the lightest tuner on the reverse taper moved along its curve. My guess is the best results are probably going to be around the region of 55 grams, so I’m looking forward to testing between 25 and 75 grams to see what happens. Did I mention 3D printers are very handy? :)
@@ClaytonMacleod Dear Sir - very interesting.......keep at it. Thanks.
What a great pod cast
Thanks so much!
From the lathe to the target, it's all about precision work, everything,
This is worth listening to💥 🌀 💨🏁
Thank you very much.
You're very welcome
Great episode! 👍
Thank you!
Why do all you guys wear headphones? Is there that much background noise or are those for prompts like Brandon gets? Hehe, seriously I’ve always wondered why you guys wear headphones sitting directly across from one another.
This guy is awesome 👌
So half inch is good then?
Hornady- hard to achieve any dispersion without Brass to load… are you ever going to offer 6.5 Grendel Brass again ???
Either fire form 7.62x39 after sizing it or just buy some ammo to have some brass. I can find some with 5 minutes of looking online. SGAMMO has factory ammunition available and if you order over 200 bucks worth you get free shipping. Midsouth shooters supply has brass and bullets in a bundle. Just look bro.
How are we getting 70 possibilities out of 4 variables to the 2nd power??
@@georgejohnsmith This must be some statistical theory or something, because again I don't see the math,
8*7*6*5/4 does not equal 70 and I obviously don't know if the included "!" has some statistical meaning but it doesn't mean anything to me. And yes I had planned on listening again
@@georgejohnsmith LoL, I'll take your word for it, I made it through Trig, and Algebra, but pre calc made my head hurt!!
Regarding when you were talking about the barrel OD in relation to the ID or bore. Search Geometric Dimensioning and Tolerancing, or GDT. Specifically, Concentricity. It is a system of measuring and describing geometric elements of features in machining and manufacturing of parts. I realize you are looking at this from the viewpoint of your specific industry. These are elements that have common names and protocol to measure them. Not trying to be an egghead, just wanted to let you know that this is used every day to describe deviation from true geometric form.
From my wifes phone. What ever happened to the outfit in Las Vegas that made a unit device that wood spin a bullet around its mechanical center and check its balance. Suppostly allot of bullet manufacturers had one of these units. It would not give you amount of out of balance, but would be used to dIffenate good balance when spun to out of balance. This device was used to sort balanced versus unbalanced. Tests were done for accuracy that proved this theory.
Dude has so much knowledge
I have gotten away from handloading cause I'm a moron and sold all my equipment throwing a temper tantrum. Now I'm working my way back to doing it now that I have come back to shooting sports. I had had a little meltdown cause I got angry at firearms manufacturers cause I felt they were screwing over their consumers by not fighting for us against administrations. I've grown up and seen it from their side that they are just trying to survive also. Best way to say it 45 year old me has learned a concept 28 year old me didn't understand called compromise. Okay that BS out of the way let me get to my point. When I was training to be a gunsmith I learned to turn bullets on a lathe. I've been a precision machinist for over 30 years. My dad was a tool maker for Bell helicopter. He taught me as a child. I've been a bladesmith and general master blacksmith since I was a child, my grandfather taught me. I've been an archer since I could walk. Safe to say precision is ingrained in who I am. I will trash a cabinet because it is off by 10 thousandths of an inch. Been known to do worse to an engine because the bore is off by .00001, I have extremely high standards for myself as a craftsman. Yeah I'm also a master performance mechanic also, started when I was 8 years old. So in hand loading I cast and forged my own bronze or copper alloy rods to make bullets. I got very advanced in it. I worked as a security contractor for 9 years as a marksman in south America. So I have super high standards for myself there also. I know why companies like Hornaday don't make lathe turned bullets, for those that don't you enjoy not paying $20 per round that is why, but if I'm going to make precision ammo I want to make the most precise ammo possible. That is a lathe turned projectile. If you intend to do this you will need to go to college and study metallurgy and ballistic performance extremely in depth. I learned it through a lifetime of doing it. Every bullet will have a specific metal😢needed for the intended purpose. Like an elk in Colorado will need a different metallurgy than a white tail in Texas. Man me and rabbit holes. Anyway, I made bullets to eliminate a lot of those dispersion factors like cog shift. Even in the methods I used it still happens sometimes. I took every measure humanly possible with current technology, and would still have it happen probably 1:1000 bullets. When it didn't happen yeah elemenating human error on the rifle (mounting it in a vise) it was possible to get same hole groups from my cheap savage axis and axis two xp rifles at 500+ yards. You go past 800 though and there are elements humanity doesn't understand yet, much less have a way to combat, that you will get dispersion in your impacts. The best I ever made happen was two inches at a grand, and I believe a lot of that was just pure luck. So the idea that dispersion is all on the shooter is BS.
Very much enjoyed it!
Many thanks!
I have found flat base bullets are easier to get to group
Never heard all this before thank you for your help.
Happy to help!
really interesting stuff
Two things. First makes me wonder how we ever shoot and hit the broad side of a barn. Second makes me think how dang good the companies that manufacture firearms and ammunition, or components, at giving us some very fine quality stuff!
I agree with a lot of your content…… but the example of the tire out of balance does no vibrate more as speed increases. It depends on the hertz of that bullet/tire. Try an experiment. take a 3oz weight off one of your tire on your car with average size tires . Drive it on the highway at slowly increasing speed . It will always be its worst at 60 to 70 mph due to the frequency in hertz
Well lets not forget that Hornady makes match bullets, and has been for a very long time.
Beyond that, some serious shooters separate bullets by precise weight, and by spinning them for balance, as well as trimming for exact tips.
Im very surprised that Hornady would produce these types of videos.
Has anyone decided how long the outside diameter of the bullet needs to be to insure the bullet is not tipped?
It’s not like above 1.5 caliber wheelbase there’s no in-bore angle; it’s more like there’s always some in-bore clearance & the longer the wheelbase the smaller the in-bore angle.
There are so many variables.....Thanks for the info...All in all....A good rifleman will.outshoot a.bad rifle!
Great information! Thanks!
You bet!
Great podcast..maddening…but great info…I foresee a lot of sleepless nights trying to concoct the perfect load..☹️
I feel like a whole episode should be done on how the balititions take care of the barrels they test with. Break in proses, if any, over cleaning, not enough cleaning, is barrel burnout from over cleaning a thing, or maybe no cleaning at all.
Plenty of professional shooters have went over this already. You can’t over clean your barrel as long as the tool you use is softer than the barrel. Barrel break in for a stainless barrel is shoot 5 then clean then repeat until 20-50 rounds and you are done. A lot of stuff you hear is “fudd” lore.
Outstanding! Moore please!
Thank you!