Kinetic energy loss in hunting arrows at 60 yards l Ashby Bowhunting Foundation
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- เผยแพร่เมื่อ 25 ก.ค. 2021
- This video is about the amount of kinetic energy at launch vs 60 yards with increasing arrow mass. 3 bows and 6 different arrows, with increasing mass and FOC. Second in a series as the Ashby Foundation starts testing.
Haven't seen speed Erosion?
Watch the first video HERE! - Arrow Speed Loss 0-60 yards: • Arrow Speed at Launch ...
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You have so many people/ archery shops mad at you all over the world
I know it. I go in my shop and I get some negative feedback. Not horrible. Dont matter tho this whole process made me a confident shooter.
No kidding. I went into the shop the other day for a new string and rest adjustment. This guy proceeded to ridicule me for shooting a 650 grain arrow, and told me that the "engineers" that design the spine charts know what their doing, even after I told him I was able to bare shaft it fine. Could not get it through his head.
@@TheDonsRiche I don’t think they know what they’re doing honestly lol gold tip, Easton...are probably the only ones who don’t have Stockholm syndrome lol the rest of them don’t offer anything above 300 spine. I was at my Mathews dealer and they had nothing but 400-340 spine arrows. And they really hate my hoodie that says shoot adult arrows lol
The hate is real!!!
...this is fantastic! Thanks Troy and all involved!
Thanks Troy aka Ranch Fairy for changing my approach to arrow setups, I've been bowhunting since 1978 arrows back then where mainly cedar shafts and zwickey type broadheads which where naturally heavy I'm now shooting 738 grain arrow with a 27 almost 28% FOC, I'm also setup for 638 grain with 20% plus FOC, thanks again Troy you are the man, happy hunting I'm pumped only 36 days until September 1st elk opener.
Love it man. Keep up the science. Thank you for trying to find the most lethal arrow set up for us so the animals don't suffer.
Absolutely love it. And jealous! I'd love to get to do these tests and shoot all those arrows. What a way to spend a few days
Thanks Troy ive learned so much from you! Appreciate you man!!!
I am shooting Easton axis arrows this year. They are 440 grains. I am getting great speeds. And perfect arrow flight. Wt a fixed blade broadhead NAP HELLRAZOR. Keep up the great work troy.
The numbers are more than interesting. Nice!
Excellent work Troy! You are conducting physics experiments and reporting the results. I am an archery hunter that teaches physics and I still need to consult texts to disambiguate your data. I am not sure if there is anyway to simplify the terms anymore than you can subtitle sitting on the couch for going into the field to learn how to hunt. Keep up the good work!!
Another amazing video!
This is great information, thank you Ranch Fairy!
Troy Thanks for the information, always good.
Troy I absolutely love it when you piss of the know it alls!!! They hate being wrong!!!
I’m looking forward to seeing where the conversion of speed, KE, and momentum come together. Basically the point where you get the minimum arrow drop at 60 but tolerable KE and Momentum. I’d imagine it’s somewhere in the 525-575 grain range.
In my opinion, it’s around 7gr per pound.. Give or take a few. I’ve shot enough arrows in my 30yrs as an archer that that’s been my experience.
RF,
I appreciate anyone who is willing to put in this much effort to share his knowledge. I would like to request another test that could be added. Similar to the long range rifle world, I think a arrow drop comparison would provide another piece to the puzzle when deciding what weight arrow to shoot. The numbers don’t lie on the tests you have done, but if I am off on my range estimation what would be the results with different arrow weights. Hope this makes sense lol.
I would say it’s just physics but to each his own. 😉
Thanks
Dean
the variation for a heavier arrow (shot from the same bow) is always higher: it is slower, so longer in the air which allows gravity longer to work resulting in a higher drop. Via adjusting the pins we adjusting the shooting angle to get the correct trajectory that allow us to hit the target. If you have the speed of your arrow, you can easily calculate the time this arrow needs to fly from A to B. With the time required you can calculate the drop as "drop = 0.5 gravity x time>>2 " for this specific distance A to B.
@@WM-jy9dz I figured there had to be some algorithm that trophy ridge uses for their “react technology”. I would like to see it graphed out for a visual. For example if I range an elk at 38 yards but he is actually 41 what kind of margin for error am I looking at depending on the factors you described. I’m enjoying all the data and discussion, keep up the good work. 👍
@@Dean-zx6nx it is actually relative easy - all you need is a chronograph to measure the initial speed of your specific arrow. The speed will determine the time for the yardage the arrow travels, e.g. if the speed is 92 m/s it would need..."34.8 m divided by 92 m/s equals 0.38 sec" ... (Note I changed the yardage to meters, and the equation for the time is "distance divided by speed"). Now lets assume you sighted in your bow / sight perfectly, and you are a perfect archer and would have hit the bullseye for this distance. However, as you misjudged the distance the arrow flies actually 41 yd = 37.5 m - for this distance the arrow needs 0.41 sec. The equation for the drop is "drop = 0.5 gravity x time>>2" with gravity = 9.81 m/s2 ...now you calculate the drop for both times, and the difference is the gap to the bullseye, in this case approx. 116 mm (if I got it right). Now this calculation is simplified as I ignored the speed erosion, but it is still good enough as I ignored it for both calculation and the distance isn't extreme. So you likely would miss your elk just ... but if he ducks with the right timing it might be a heart shot.... 😀. Now do this calcs with a much slower arrow, lets say 60 m/s and you will find out that the error margin has dramatically increased to 266 mm which means that your elk is highly likely gone.... 😒
@@WM-jy9dz I truly appreciate the time, amazing. It was much simpler when I was young and my dad would say just let it fly. Lol. Thanks for the equation, looks like I have some homework to do! 😅
@@Dean-zx6nx all credit to Troy for all the effort 👍 and throwing all this data at us so we can have a livelihood discussion 😀 ...
Troy you're awesome. This video got me thinking. I think it would be more impactful to most non believers if PSI values for the very tip of the broadhead could be shown for those same arrows.
Interesting. I’ve received a bunch of ideas like this. We are working on how to do that. Honestly from the crude experiments we’ve done trying to figure this out. You may not want to know how much extreme force a punch point / mechanical requires just to break the skin of a pig.
To those reading this - key point here - the top line (launch KE). Is basically flat.
The 60 yard KE line IMPROVED consistently as mass goes up
Yet speed went down.
Newton and basics physics.
Stay tuned
If you are able to do a test with traditional bow, that would be awesome! 🤙
Enjoyed your past few videos on kinetic energy down range. Very important on archery hunting downrange. Most measurements are done 3 feet in front of the bow. Opened my ears as a beginner archer. Somewhat similar to using a great dart possibly?
I am not on the “heavy arrow” bandwagon. I do like these studies because I love math and physics. The caution here is that people doing studies that already have preconceived notions will align the data to prove their point. We see this in marketing everyday. I like RF and am not saying he would skew any data in his favor. I will be anxious to see what comes out of all this work. At least he is willing to put in the work.
Heck yeah - I was actually QUITE surprised by the 60 yard KE math. I figured it would trend along the launch KE line - which is not really that interesting. Stay tuned - momentum is VERY interesting
If you really cared about the math and physics you would know that heavy arrows are superior. Momentum beats energy, mass beats velocity for momentum
@@brads5065 even Ashby says that you have to stay within “acceptable trajectory” which is that line where heavy is hurting instead of helping. That is what some have forgotten, and I am interested in.
@@steve8828 Sure, and I wouldn't fling 650 grains at an animal 100 yards away, or even 60, but the vast vast majority of archery hunters hunt in fairly close range, and should definitely be using heavy arrows. Maybe I misread your comment as more critical of heavy arrow builds than intended, but the default should be firing heavy bone-breaking arrows, and people should only deviate from that for good reason.
@@brads5065 ..."mass beats velocity for momentum" ...really? ...that might be your opinion, but it is not math - momentum is mass x velocity, if you increase mass by 20% you will increase momentum by 20%, if you increase velocity by 20% you will achieve the same result - a 20% higher momentum.
Perfect, I get the answer to my questions I've developed
Went to an archery shop today. My son bought both of my grandsons their first compound bow. While there, I asked the tech behind the counter if he ever watched "the Ranch Fairy"...his exact reply...."God no, I don't watch that idiot"
Thirty minutes later, he stepped out into the range and watched me shoot my 648 grain arrows. As they walloped the target, he asked me why I shoot such heavy arrows. My exact reply..."Watch the Ranch Fairy" haha. You're welcome.
Haahahah - that’s awesome
Spot on man! Cant argue with the labradar
I can't wait until the momentum video. Speed & k.e. r like relative humidity. 28* & snowing with 88% humidity or 92* with 88% humidity & almost raining. Dewpoint & Momentum r similar & give u the truth or @ least something that isn't debatable.
Was just sharpening my 2 blade VPA broadheads when this popped up.
It all makes sense once you understand looking at this from a math perspective. Math is math and it’s pretty easy to see that the heavier arrows are retaining the kinetic energy over range better than lighter arrows. Thanks for the info!!
Hey Troy after studying Ashby’s finding and your findings. I went from a 70# 26.5” 438g 340 spine arrow about 9% FOC with a mechanical. I’m now shootin 75# 26.5” 630g 250 spine 23.4% FOC with a VPA up front. Just from my findings penetration depth with a field point at 20yds and 100yds is only a couple inch difference. But groups are tighter and more consistent. And I have yet to bonk a deer with my heave set up everything has been a pass through. Going to the elk woods this September, just wanted to say thank you to you and Ashby!
shooting such a high FOC @75# with a 250 spine your arrow is heavily underspined - you might get away with a mechanical (still not ideal), but a fixed BH would for sure cause a lot of planing. Let's not forget that Ashby ranks "arrow flight" as the second most important parameter (after structural integrity), FOC and mass etc. comes behind.....
@@WM-jy9dz my groups only open a little at 80 I got from 3.75” group with field points to 5” with vpa single bevel
@@WM-jy9dz
Well, he’s running 26.5” shaft which is perfect and is stiffer than 250. I bet he went through “the process”. No one on TH-cam FOCUSES and offers more strategies to the everyday archer (bare shaft) to achieve perfect arrow flight - than the old RF.
@@RanchFairy so the arrow manufacturers with their charts are all wrong? ...a good spine calculator that is capable of calculating the dynamic spine takes that shaft length into account - show me the arrow with a 250 spine and a TAW of 630 grain that can cope with 75# and an FOC of over 23% .... this arrow doesn't exist.
Eta: did some calcs with different shafts of different manufactures - *and I was wrong* ! there are arrows with a 250 spine that are well balanced for such a setup, e.g. I run the Victory RIP TKO with a 250 spine through the simulations and they are perfect (you could actually add 30 grain more to the front) .....I learn something everyday 😁
@@bucksnbeer4241 you must be a good shooter 👍 - nevertheless I bet that the wider grouping is more to the right of center shot (assuming you are right handed) which is a sure indicator for a weak spine.
Eta: it can also help if the single bevel BH rotates the arrow in the same direction the fletching does (you don't want them to turn the arrow in opposite directions) - this helps with stabilization, but comes with the trade off of higher speed erosion.
Heavier arrows for the same drag have greater sectional density resulting in a better ballistic coefficient. FOC helps further move the centre of pressure from centre of gravity.
wrt BC: ...that would be only correct if you shoot a bare shaft without fletching - usually the heavier arrow will need more fletching ... and there your better BC goes down the drain 😎
@@WM-jy9dz
Another person who is reading the message boards. Actually when you move the center of gravity forward (more FOC) the “flying stick” gains stability. It requires less fletch to stabilize.
So I’ll play along. Let’s say you use 5” high helical tall vanes - spitball weight 10 grains each
30 total grains added to an arrow.
Point weight was constant.
You are correct - CG moves more central and destabilizes the Arrow.
However - you could add 30 or 100 or 150 grains to the front and move CG forward - quite easily.
Most people don’t understand that I’m archery so it’s cool to see these kind of comments and chat about solutions.
@@RanchFairy as long as we have a kind of target tip setup, more FOC (needs also the right spine!) may minimize the required fletching, however, a broadhead (a real one, not a mechanical 😁) will require most of the time some more help with steering / stabilizing. With such a "wing" on the tip, even if the spine is just perfect (not too weak, not too stiff), there is always some flexing at arrow launch that can be enough to cause the arrow planing. The difference between bare shaft and a moderate 3 vane fletching with approx. 1.5 deg offset is easily in order of 10 fps indicating the dramatic impact fletching has on the BC. (If you want to test this make sure you compensate for the weight of the fletching when shooting bare shaft - some chewing gum, carefully weighted 😀, inside the shaft at the end of the arrow will do 😁)
It would also be cool to find out the duration of time different weight arrows are in the air at at different distances. You can divide distance by fps but what we don't know is the acceleration (deceleration, it'll be negative) the arrows are dropping velocity. If heavier arrows drop velocity less than lighter arrows... then the delta will be similar to what you've shown here.
I'm new but I eat this stuff up. Ty RF
Troy, is there anyway you could post the data from this experiment? I'd love to be able to see all of it myself.
There's a jump in there around 400-550 gr. I'd love to see more arrow weights (smaller intervals), 25gr intervals, in that area.
I'm definitely not smart enough to follow all this math crap haha.. love the video and love that guys are learning stuff. I'm trying but I'm a knuckle dragger and some things just don't comprehend to me. Keep up the great work Troy 💪
To the Fairy of the Ranch and the Man of the Rockets: I love the math! Keep it coming. I imagine after a year or two you guys will have some good penetration models like they have for handgun wound ballistics. With handguns and flat nose bullets or hollow points, assuming they mushroom consistently, you can put in weight, speed and final diameter and predict ballistic gel penetration to within 5% with some fancy quadratic polynomial eponents equation stuff.
Ballistic gel friction is so high on an arrow so I have always wondered about buttering up the shaft with some vaseline before you shoot (lol) to more fairly compare arrow penetration against dangerous game bullets and varmint bullets. If the friction were more equal you could show kid arrows penetrating like a 243 and adult arrows penetrating like a 45-70.
Anyways after you two smart guys work out the math you can find some inflection points on the graph where slow heavy arrows from trad bows equal penetration from faster but lighter adult arrows from compound bows, and at what point a slow longbow adult arrow surpasses a twizzler out of a compound. After the math is figured out you could find out fun stuff like at equal impact speed, but unequal FOC, what amount of FOC is needed to overcome 100 grains less arrow weight at the same speed. For example, a 550 grain arrow 10% FOC vs 450 grain arrow 25% FOC and the math shows they are almost equal in penetration, the lighter penetrates more, or the heavier penetrates more.
Onward ho!
And yes - ballistic gel is likely the worst medium for arrow testing on the planet
...somewhere through the comments I made the statement that a high arrow weight needs more (=heavier) fletching as it requires more steering - and Troy confirmed it somehow with some calcs. Now, this is actually not always true, here is something the high FOC fans will like to hear: if you increase the FOC you don't need necessarily more or heavier fletching. Reason is (I think I got this from a clever guy from ironwill) that when increasing the FOC you (the name says it) actually moves the centre of gravity more to the front, thus INCREASING the distance (LEVER!!!) to the fletching, thus increasing the MA for the same amount of drag, hence not more fletching surface required (at least if you can stick with the same spine / GPI arrow.)
Thank you for the in depth explanation of your experiment. It will be interesting to see the end result of your experiments - meaning what arrow weight is optimal and where the threshold begins for arrow failures due to lack of weight. I have only received a definitive answer at one archery shop, wherein the owner had a specific weight that he advocated - no less than 500 grains. Can't wait for your non-equivocating answer.
Better than one of my local shops. I went there a few years ago (before I knew about the Ranch Fairy) and told them I was going to jump up to 125 gr. broadheads from the 100 and they looked at me like I was nuts because I wanted a little more mass and wasn't ONLY thinking about speed. They've changed their tune some now. Last year I was talking to one of them and said I was doing heavier arrows. He didn't act like I was committing some atrocity to bowhunting. They didn't have any arrows above a 300 spine except for the FMJ's but he pointed me to a few places where I could look. I'd be willing to bet the next time I'm in there they have at least some stuff for heavier arrow, higher FOC guys.
My question that I'd ask is; is the a sort of bell curve situation where eventually the separation of initial KE vs 60yd KE starts to drop again? Between speed, KE, and momentum if it is a curved situation you'd be able to figure out exactly what arrow mass every person would be trying to achieve to maximize "efficiency" in their arrow setup.
Keeps going up with mass - here.
But i’ll ponder the idea.
Ashby reports have the most solid info on impact, on animals. That’s the X factor - critters aren’t a fixed KE recipient. Depends on what you hit - in the animal.
Great question. More to come.
How would I get involved to help yall? I think I'm fairly close to you and think it would be a blast to help yall out
It’s all about momentum. Mass AND velocity! Like anything, find the healthy balance.
Troy, do you have plans to compare the trajectory of each arrow weight?
LOL! hell no. Lobbing rainbow's doesn't fit the narrative.
@@wiscofun3028 Each arrow design decision gives us an opportunity to choose between positive and negative trade-offs. I'm just interested in understanding what those trade-offs are so that I can make the most informed decision possible.
actually you can do it on your own: shooterscalculator.com/ballistic-trajectory-chart.php while this is for bullets it also works for arrows. A few notes so: for "Drag Function" use "G1" - it won't make such a big difference as arrows are much slower than bullets anyway. For "BC" (ballistic coefficient) use something between 0.04 to 0.18, use 0.18 for a thin but heavy arrow, 0.04 for a fat but light arrow ...if you have something between use something around 0.11. You need to know the speed of your arrow fired from your bow (chrono!). "bullet weight" would be the total arrow weight. "Sight Height" is the distance from the centre of your peep to the centre of your arrow at full draw - best measured with a draw board. The "shooting angle" is zero! - the adjustment for the angle is reflected by the "Zero Range": if you sighted in your pin sight, and you shoot the 60 yd - the 60 yd is your "Zero Range", if you use your 30 yd pin and shoot the 30 yd then the "Zero Range" is 30 yd.
If you play around with the graph and you wonder why it might look the same for different entries: have a look at the right axis - this is where you recognize that the drop changes. I'm still checking how precise the calculator is for arrows, but for a start, when I compare it with my own Excel sheet, it looks pretty reasonable.
if you want to do a little bit more reading: sites.google.com/site/technicalarchery/technical-discussions-1/drag-coefficients-of-bullets-arrows-and-spears
Eta: after some tinkering ....the figures for the BC from the later link seem to be too optimistic (I guess they don't consider fletching) - I get reasonable values / graphs when I use BC = 0.02 for my VAPs with 3x 2" vanes, for thicker arrows, bigger & more vanes, and bigger broadheads you might try 0.01 to 0.015 for BC.
Great data 👍! ...but head didn't pop off 😁 ... as mentioned in my post in your previous video it doesn't come as a surprise that the KE losses are higher for higher speeds, that's just the physics. Now the big question is: is the KE left for faster arrows enough for good penetration? I guess we can agree that a faster arrow helps with targets that might move, but is it worth sacrificing KE for it?
Now here some ideas you might consider for your next studies: the penetration will depend on how much stress / pressure the blade(s) of the broadhead can apply to the skin-meat-bone-tissue matter - e.g. a 30mm wide cut from a 2 blade broadhead will require *DOUBLE* the force / work for a pass through than a 15 mm wide cut from a smaller 2 blade broadhead (assuming that both broadheads have the same sharpness). This work for the cutting has to come from the KE of the arrow, and while the KE losses are higher for faster arrows, the effect a bigger broadhead has on penetration can actually be much more compromising.... some food for thoughts.... 😀
Eta: e.g. while you might have 20% higher KE losses wrt light arrow vs heavy arrow, you could easily compensate for this by reducing your total blade length a little bit....and then you would still get your deadly pass through, but with higher accuracy and delivered by an arrow that will hit the game significant faster thus giving the game less time to move.
Look up Brandon Mcdonald he did a video where he overlapped his shots. With 3 arrow weights I think and timed them all to eachother.
@@jhuntnfish6872 I saw it - Brandon contemplated also whether the difference of 0.1 sec the heavier arrow needs longer to the target would make a difference. Think about this: if your arrow travels with 90 m/s (approx. 300 fps) this 0.1 sec means whopping 9 meters !!!!!!!!!!!!!!!!!! the lighter arrow is closer to the target!
furthermore: conversely to a bullet, usually even a fast arrow still travels with a speed that allows you to watch it flying - I would assume that the eyesight of a deer, pig, or goat is at least as good as our eyesight, if not superior. Hence IMO there is a massive advantage for every fraction of a second I can shave of the arrow's fly time....
@@WM-jy9dz yes your opinion correct. It sounds like you are confident and don't need to change anything good for you sir. Have fun with your 3/4 ounce arrow.
Very good video as always free your mind and your ass will follow keep putting them out.
Very insightful… The speed erosion is no surprise to me... It’s just intuitive. What I found interesting is that KE at LAUNCH was higher for heavier arrows. I always believed the opposite since KE = 1/2 * mass * velocity^2… so in my head higher speeds would drive KE up more than the heavier mass. And the various “archery calculators” online that calculate speed and KE from my specs always show higher KE from lighter arrows. The nerd in me would love to get ahold of the raw data from your lab radar testing.
a lighter arrow will facilitate that the spring energy stored in the bow can be transferred faster, thus the cams will rotate faster, the limbs will swing faster; this causes higher internal friction losses, thus reducing the energy that can be transferred into the arrow. In other words: the bow works less efficient for lighter arrows. The 5 grain per poundage is the common accepted threshold - if the arrow is lighter you start dryfiring your bow as the internal losses become too high.
Eta: it is similar to a car you drive from A to B: the faster you go, the higher the fuel (=energy) consumption ...but the distance is always the same....
Some of the issue with the archery calculators is they assume a 1 fps loss for every 3 grains weight increase, but in reality the speed erosion from higher weight arrows isn't as drastic as calculated. In other words if you increase your arrow weigh by 60 grains you should loose 20 fps according to the calculator, but in reality the lose may only be 15,
@@ngnmech those calculators (well, most of them) only give you the approx. speed at point blank - they don't calculate the speed / speed loss after 10, 20 ....30 meters ....
@@WM-jy9dz well the point I was trying to make is that those calculators are apparently wrong even at point blank speeds. Just look at the KE numbers in this video. Every heavy arrow has more KE than every light arrow AT POINT BLANK. If you run different weight arrows through all the online calculators, they consistently give higher KEs for lighter arrows at point blank before any speed erosion has begun to occur. That is the most interesting part of this video to me. TBH it’s kinda hard to believe ALL the calculators could be so wrong. How would no one have questioned or tested the accuracy of their predicted speeds before now?
@@HuckFTW all the speed calculator apps I know will require to enter the IBO speed at one point - and that's where you recognize the results can be only indicative.
Not sure if it's totally relevant for this video but would love to hear ol RF's opinion on the FOC king arrows. Gimmicky or no?
Couldn’t get them to fly and price point is really not something within my audiences reality.
I've been asking on the hunting public videos, but do you plan on doing videos on crossbow bolts? I'm stuck using a crossbow due to a shoulder injury. I'm wondering how my 492 grain bolt compares to a 600-700 grain arrow at impact. Does the rigidity and speed overcome the lack in weight? No one seems to have the answers I'm looking for.
Search ranch fairy crossbow
Dude did a whole series
@@RanchFairy Thanks!
great info.... way better than those who just call BS on you only using 800grain arrows.... and also calling hunting pigs n whitetail soooo different than mulies n elk. you do the research they do the BS-ing!
That’s why the info is at 60. The long range guys need to pay attention. Just because you hit them
Doesn’t mean you kill them.
@@RanchFairy the funny thing is they keep bringing up the 800 grain bombs! then i got the reply from Dirk the bugler about his 3 decades of killing elk.....lol
Nice. Thanks Troy. I knew I shot a 600gr arrow for a reason. 😜
Hook me up with one of those hats, they fire.
I'm not arguing anything I think both heavy arrows and light arrows have their advantages and disadvantages, However, You do realize Dr Ed Ashby research was all done and about traditional bows that you are transferring over to compound bows. However I am glad you are doing the research to see how it works with Compound bows. You might change the game.
Even though the original testing was done with traditional gear, the science is just as valid for compounds or crossbows. Longbows recurves, compounds, and crossbows all function the same way, by storing energy in the limbs and transferring that energy to the arrow upon release. A well-tuned accurate, and heavier arrow will aid in penetration for all archery equipment. The argument by many in the compound world is that heavier arrows impact the velocity and trajectory. I think that is a small concession for the advantages you gain.
@@bowhuntznj I believe in having some weight in the front but having weight in the ARROW as well, Think of the argument about a MOTORCYCLE HITTING A WALL vs a SEMI with no or an EMPTY TRAILER HITTING A WALL, Now take that same scenario and have the SEMI LOADED with 80,000 lbs in the trailer hitting the wall vs just the tractor hitting the wall. Just like Ranch Fairy says it all in the MATH. and the math will show a HEAVIER ARROW helping shove that forward energy will give you better results than a SUPER LIGHT ARROW and mass weight in the front.
@@TyrantExterminator1776 your analogy with the vehicles would be correct if all of the vehicles will run with the same engine and with the same fuel (energy) consumption as this is the case for a bow: the max. energy is limited to a threshold by poundage and draw length while that semi has likely a much bigger and powerful engine that consumes more energy / fuel than the tractor. The question wrt a bow with the predefined available energy is how we want to spend this limited energy: faster arrows sacrificing more of the initial KE, or a slower arrow with less loss of the initial KE. If you can outrun your arrow I would say the arrow is too heavy for your bow 😀, and if the arrow is so light that (while starting with an extreme initial speed that nearly causes a dryfire scenario for your bow) it will consume most of the initial KE that results in such a slow speed after a few meters that you will be able to outrun this one too after some meters, than this one is definitely too light 😀 ... so the optimal weight will be somewhere in the middle pending on what you hunt and at which distance your arrow needs to be effective.
I want to get your thoughts... I'll just run the #'s for you. 300 spine blackout x3. 150 grain brass insert and a 125 grain cut throat broadhead. 28.5 in draw @ 68 lbs...
Good idea for white tail in Ohio?
I don't have the spec for the blackout x3 with a 300 spine (maybe you can publish it here), but with 275 gr at the front it might well be that your arrow is underspined, and you know what this means for "arrow flight", which is the second most important parameter (most important is structural integrity) on Ashby's list for success, FOC ranks only third!
Hey Troy it wouldn’t be exact science but it would be “pretty” to see lol. Any thoughts on shooting ballistic gel at 60 yard with the same arrow set ups here?
None - ballistic gel is probably the worst penetration measuring substrate on earth. It is 100% designed to stop things
Long sticks really grab in gel. So any video you see measuring penetration, which these folks then think is directly applicable to hunting.
Nope - they are doing a gel test.
In gel - that’s the results.
My reference point is 1M + arrow impacts on you tube
Penetration is all over the place in live hunting video. More to come on this.
Does this only matter with high FOC? I shoot CE pile driver with 125 gr. heads total arrow weight 523 with 11% FOC. Is the real power in momentum or KE?
Mass over drag here
We will add FOC later
Momentum is the number
That video is coming soon
I would love to see the effect that poor tune has on speed erosion. Take the some arrows, get them fairy magic tuned, shoot them bareshaft and fletched through the radar, then start messing with them to get them out of tune, and shoot them bareshaft and fletched through the radar to see what poor arrow flight does to your speed over distance. I gotta think that any wobbly/knuckle ball flight is going to affect speed some kind of way. Perhaps another way to test it would be to build arrows of the same weight but one with correct spine and the other slightly incorrect. Might need to take multiple shots of the same arrow and average them to get something close to accurate to compensate for the wonky readings of the radar (could also calculate variation and do some whisker plots to investigate variability as well). A slightly out of tune system with an arrow flying a little cockeyed shouldn't throw the machine off too bad and should increase the drag enough to slow it down over distance. My hypothesis is that out of tune arrows will slow down more and have greater variation (less consistent thus less predictable) speed erosion over distance.
To sum it up you loose 5 ft lbs of energy at 60 yd firing a sub 400 gn light arrow on a dual cam bow vs a very heavy arrow at 550 gn. You will loose 5 ft lbs more on a long shot, is it really necessary to get penetration. 5ft lbs is about 7% of your initial energy. This is at 60 yds too. Is it worth it to fire a slow arrow with greater drop and more possibility for a miss with an animal that moves or is ranged improperly or do you need an extra 5ft lbs of energy stab a pointy stick through an animal. To be honest if your shot is in the right spot and you have a good broad head, no.
If u continued that test with heavier and heavier arrows 1000+ grains, at what point do u think the erosion would be almost 0? Basically what would be the "perfect" grain arrow for this chart?
...that would be an arrow you have to carry to the game, hold it 1 meter above it and then just let it drop ...and if the game didn't move in the meanwhile it would be dead on the spot ....alternatively you could use a medieval catapult, but with a catapult there is speed involved, so we would have to cope with KE losses again 😂😁😂
@@WM-jy9dz You are missing the point. This is about ethical lethality. Optimizing and determining the real effective lethal range for your personal setup and skill set. Why not have the best setup for your prescribed hunts?
Speed only focused setups are being justified as an excuse for not doing proper diligence as a hunter.
Example: With my ultrasuperduperxtreme levitation arrows I can use 1 pin out to 177 yards mentality. That way, if I am off 43 yards on my shot estimation, I score. Or with my 22” wide cut broad-head mentality all I have to do is hit someplace and I score.
Bow hunting is NOT a sport. It is the harvesting of game.
It is not a number on a chronograph or a hole in a foam or paper target. The wild game we pursue deserve our best.
R.F. Is reporting the data for everyone’s benefit.
Listen, learn & try it out. It works.
Or...
Trolls gotta troll.
@@rickbiggs6629 if you want the best setup: take a rifle! ...otherwise I understand that some people prefer a broadhead that is suitable to decapitate the game in case they don't hit the vitals, others prefer a clinical pass through ...
@@WM-jy9dz R.F is providing proven data.
It's up to you to give it consideration or not. Shoot what you think is best. Just give it your best for the game to be harvested. Peace out Bow Brother.
I have shot at my bags multiple types. And my 683gr arrow hits harder at 100yrds then my 440 did at 20yrds. And they fly like little spears. I have no doubt they will zip right through when I have the encounter.
...your are talking about a medieval trajectory here? ...than I guess you are right 😀. In case you don't test your hitting via clout shooting, but with a more normal trajectory the 80 yards your heavier arrows have to fly further will eat all the advantage the heaver arrow has wrt KE loss advantages (just have a look at Troy's diagrams ...)
@@WM-jy9dz do some imaginary arrows in some Calculators that show out to 70 or 100yrds and see for yourself. I mean I have 5 pins and will shoot to 60 with no real thought difference than with the lighter arrow I used to have. Oh but in oklahoma where I hunt my new arrows are almost Un effected by wind. So now I will shoot way more confidently.
Good stuff as always. First they scoff, then they make fun, then eventually they say they knew it all along. Just wait and see.
But you can’t shoot that heavy out west elk hunting Troy!! (Kidding, just poking fun from recent videos from elk shape who won’t actually call you out)
I know man. I’ll get to them.
I love the math, but I think you need to demonstrate it. Take the next big pig you kill and use it for a penetration test. Light vs Heavy at 20, 30, 40, 50, and 60 yards. Having an actual visual comparison will go a long ways.
Or maybe even find a way to do a test that calculates minimum penetration force.
I would love to see this. Physics tell us that penetration depends on the pressure / stress at the blade (the smaller the cross-section the higher the pressure is that is caused by the same force, and the easier it is to overcome the resistance of the matter against being cut). A "good" arrow should always be good enough to achieve a pass through while doing sufficient damage to blood vessels on the way through. There are a few parameters that can be addressed to increase the penetration capability when it comes to arrow building:
1. broadhead size / blade length: while a shorter total blade length will make penetration easier, a reasonable length needs to be maintained to allow for lethal damage. The optimal cutting size will also depend on the size of the specific game (e.g. rabbit vs elk).
2. arrow diameter: half the diameter and you half the surface that will cause friction on the way through the animal.
3. fletching: heavy arrows need heavy fletching, right? ...the fletching will work as a parachute on the way through the game (if it doesn't come off at the entrance), and I guess that a lighter arrow that flies perfectly with a 3 vane fletching will definitely outperform an arrow that needs a 4 vane fletching with eventual longer vanes when it comes to pass through capability.
wrt poundage and draw length (these parameters are responsible for the initial KE - of course the higher the initial spring energy and KE, the more options you have!!!): usually we can't change this (well, you might be able to built up your muscle strength to shoot a higher poundage), therefore we have to take these limitations into account when addressing the arrow parameters above.
This would be fun to get with you and run these same arrows off a 70 and 80lb bow
Yep.
Would you rather get hit in the head with a foul ball that was a baseball or a wiffleball if they came off the bat at the same speed? I'm guessing the optimal weight for max KE for a bow setup (where the line turns to curve down) is limited by the equipment. Here's an idea to research: Determine the amount of KE required for a given animal, or class of animal (ammo companies do this with their marketing, here it would be a "plan B hit" for a given animal) and solve for the optimal KE range. That would be a new standard that would be ideal for "tinkerers" to build arrows by. The bonus would be some data on width of broadheads in relation to KE. If Ashby said there's no such thing as overpenetration, I would add that there is such thing as optimal penetration, which would be maximum wound channel that still allows for a pass-thru. Rabbit holes everywhere.......
I have a question for you heavy arrow gurus. My current arrows are 487 grains total, my bow shoots them perfectly out to 80 yards point of impact dead center target. I went and bought some Apollos, they are weighing in at 547 g total, point of impact is 4 inches high at 20 and almost 12 inches high at 80, this is blowing my mind what is going on here???
Mass / drag.
Ballistic coefficient
likely the stiffer spine of the Apollos? ... a stiffer spine can cause this as it won't flex as much "around" the arrow rest (less "archers paradox") thus the arrow shoots higher. I made same experience with a 300 vs a 350 spine arrow - the 300 spine arrow hits higher.
@@WM-jy9dz
Mr Werner has some solid points here
But we don’t know the first arrow spine
@@RanchFairy I'm guessing here - it actually could also be that the arrows have the same STATIC spine, but due to a higher GPI of the shaft and using the same insert&BH configuration (=same weight at the front) you would change the FOC thus you would also change the DYNAMIC spine. Then the arrow with the lower FOC (that's the one with a higher GPI of the shaft) would be the stiffer one thus has the potential to hit higher too. (I spend quite some time over this trying to use the same sight configuration for arrows with the same weight, but different spine - I gave up at the end as the stiffer one always hit higher.)
@@WM-jy9dz
Agreed
The arrow that is lower FOC has a center of pressure closer to the center of gravity and WE THINK it bends more going down range = inefficient.
The model rocket guys know this
We are exploring -
It could also have something to do with the FOC - literally pulling.
Whatever it is - when I started crossing 16% FOC and decent tune (early on)
My arrows started behaving - more consistent.
I shoot a .22 hornet at deer. I like to hit them in the ear. I kill pigs with it too. We seem to agree on archery. My bow doesn't shoot 2500 fps. I demand that it gives me a consistent point of impact. (The human aspects come into play). Keep preaching! I am not shooting 600 grain points. A dull, poor flying 600 grain head won't help. I love what your doing.
That 388 grain arrow isn’t mine! I was just holding it for a friend! I swear!
Ha
Energy: potential of the arrow to do work. Momentum, arrow's resistance to slowing down or changing direction. Momentum is the proper data point, not speed and not energy.
Yes, we know this
But the standard speech in archery is speed and KE. So I had to start there
Momentum coming -
@@RanchFairy Oh, I know YOU know. This comment was mostly aimed at the archery community, insisting on using KE.
Too hot to fish... Welp ok let's discuss how force is directly proportional to the rate of change of momentum with time shall we 🤣👍🤣 A+
Drag is annoying, I remember doing the integrations for them in physics.
Micro diameter will absolutely hit harder down range all other variables equal.
I don’t know - mass is mass
Guess we can test that
@@RanchFairythat would be awesome
Only thing I would see with that is less drag and velocity erosion. It might be minimal advantage at best on impact but it does help as it goes through
micro diameters won't have a big impact on flying (some advantage under windy conditions), but will reduce the friction for a pass through distinctly. If you half the diameter you actually half the surface that will cause the friction. If you ever got a penicillin shot and you compare this with a vaccine shot you know the difference 😂 ....
@@WM-jy9dz
So first
Structural integrity
Perfect arrow flight
Then worry about this micro stuff
I have my concerns about the outsert systems…..trust me - it’s not like I don’t have them. Playing in backgroudn
Way too many people are out there talking out of their ass about this stuff not knowimg what they are talking about. The scary thing is there are a lot of people out there with a platform talking like that and leading people down roads that are not supported by data. Most people don't love data and using it to make decisions. Troy is a gift. His curiosity and endless pursuit of knowledge is commendable. He is not one to talk out of his ass. He can back up what he says with indisputable evidence.
Thank you.
Long story short, the heavier the projectile, the harder it is for Newton to shed kE over any given distance
Nope, that's not correct - the losses (not the actual KE) have nothing to do with weight, only with speed / drag. If a heavy and a light arrow travel with the same speed, they will have the same KE losses....
From the video:
SAME TWIN CAM BOW
Example A : 388gr arrow at launch had 70kE @ 60yds had 56kE loss of 14
Example B : 718gr at launch had 73kE @ launch and @ 60yds had 64kE = loss of 9kE
The heavier arrow started with more initial kE, shed less kE, and ended with more down range kE @ 60yds despite being slower.
The lighter, faster arrow, lost significantly more energy over the given distance (60yds)
What I just stated is verbatim from the experiment. Even with the “fast bow” set up, the experiment was repeatable across all bows used.
Despite all this, the momentum info from the experiment should be the interesting part.
@@flounderwetspot8524 the losses we talking hear are caused by air friction / drag - these friction losses depend only on speed and shape. The total losses shown in the diagram are higher for lighter arrows because the initial speed was higher for the lighter arrow (plus the higher internal losses in the bow). If you would compensate for the heavier arrow by increasing the poundage, thus facilitating that both arrows (the heavier and the lighter one) fly with the same speed, the friction losses (that will eat the KE) will be the same (assuming that the shape of both arrows would be near identical).
@@WM-jy9dz so if I’m understanding what you saying, if you lowered the speed of the lighter arrow to match that of the heavier arrow, the kE loss would be linear, or vs versa sped up the heavier arrow to that of the lighter arrow the kE losses would be linear?
And despite being linear, the heavier arrow will still carry more kE strictly due to mass, inertia, and momentum?
Example : throw a popcorn kernel at 80mph and it might sting, throw a brick at 80mph and your ass is grass
@@flounderwetspot8524 nearly (the friction losses are exponential / increasing exponential with speed - that's why a car with twice as much horsepower won't be twice as fast) ...and yes wrt the popcorn analogy 😀
Eta: but keep in mind that due to the much bigger "cutting" surface of the brick the popcorn might be still better when it comes to penetration 🤣🤣🤣
Dang my 800 grain arrow isnt on the chart
My apologies
It’s to the “right”
More KE launch
Narrower KE at 60. Just saying
Equations work like that
😂 😆
@@RanchFairy haha i was joking. Sorry i know you deal with a lot of trolls. Fantastic video series
@@droogbear649
Oh I could smell what you’re stepping in. Sarcasm - Language of the intelligent!!! However - someone needed the “answer” I sent ya!!
Blam!
Troy. I follow you in all aspects. What you are doing is great. However, you are only selling half the story err 84% maybe:) Arrow drop at range affects your ability to get in a good shot especially with an animal on the move. I’m not advocating a 220gn arrow. But, if you really want to be scientific, math nerds, rocket scientists etc. we should factor all relevant data not just the data that sells our narrative. What’s the drop between 60 and 65yds for a light arrow vs a heavy arrow. That along with the ke loss at distance is the balance many of us try to strike. I want more ke but not to improve penetration of dirt. It’s harder to find an arrow buried twice as far in the ground :)
Troy (and Dr Ashby) advocate using the heaviest arrow that still gives you a trajectory that you are comfortable with. I've never heard him say otherwise.
@@stuponfucious7 I love what Troy is doing. What I am saying is to show the relevant data. Otherwise it’s not a complete picture. For example, let’s say an 800gn arrow drops 20” from 50-60yds, wouldn’t you want to know that before you go out and build your arrows? Or do you just want to hear that you max out your ke and you lose less ke at distance. Ra ra more penetration. Troy’s research which I believe is important only gets better by including this relevant data. Data which is time consuming to collect. But if collected, coupled with the ke research would be some really eye opening data especially for us westerners :)
@@RVExodus That's fair. I suppose Troy is operating on the unfortunately too often erroneous assumption that people are going to actually *test their gear* before committing to an arrow build and taking it into the field.
@@stuponfucious7 oh boy! You have way to much faith in the human race :) I first came across Ashby about 12yrs ago but didn’t have the archery knowledge to fully digest it. That said, a buddy and I placed a chrono at 60yds with a piece of plywood in front of it to avoid shooting literally through the chrono. We got some good data. The radar Troy used is awesome. I’ll assume it’s out of my price range. That said, I agree, everyone needs to do their own testing. I do look forward to seeing where Troy goes next. I hope he does address arrow trajectory at some point.
@@RVExodus I've found this calculator to be pretty decent. www.bestcrossbowsource.com/crossbow-arrow-ballistics-calculator
💪🏽🇺🇸🏹
A man convinced against his will is of the same opinion still. Some folks are just not going to buy in no matter what. Speed at distance is of no value if you can't hit the vitals. A clean miss is better than a wounded animal any day.
...the likelihood of missing the vitals are definitely higher with a slower arrow as it gives the game much more time to react ...but that might not matter for hunting turtles 😀
@@WM-jy9dz And yet somehow people have managed to kill animals for thousands of years using stick bows and heads chiseled from stone. Not recreational hunters, people who HAD to kill or their families starved to death.
I look at it this way, Thousands of animals were harvested with bows shooting 180-220 fps for years, but if you listen to the so called experts 280 is too slow to reach an animal before it moves out of the way.
@@PoeOutdoors mankind survived thousands of years just with spears, sling shots and bare bows - that doesn't mean that a modern bow or gun wouldn't outperform an older weapon. And I don't think this is the question here....it is everyone's own choice how much he / she wants to challenge him/herself by choosing the equipment he/she prefers for hunting. Modern technologies and materials (e.g. aluminum arrows vs. timber stickers, then carbon vs. aluminum arrows) have always been game changers, not only wrt bows, but it is up to you whether you want to jump on it or whether you prefer the things that worked for you in the past. I appreciate Troy's efforts that allows us to have these livelihood and inspiring discussions on his platform, but lets not fall into the trap that we have to convince everyone that "what works for me has to work for you too" 😀.
@@WM-jy9dz. I agree. The context of the video is speed erosion over distance. The lighter faster arrows are not going as fast as you may think they are over distance and at impact. Consequently, the slower heavier arrows may be going faster than you may think they are and at impact. There is a happy median in there somewhere. It's going to be different for each of us.
Over thinking this way to much. Shoot an arrow from 450-500 grains and your good
Guess the math didn’t make sense
Ok!!
There’s also
Structural integrity
Perfect arrow flight
Arrow tuning
Perfect broadhead flight
So yeah - there’s a lot to think about
why, after all this math and graphs and showing the facts... do the low-weight winger-zingers STILL not see that there might be some truth and value in the heavier arrow/slower initial speed path?
...the truth I can see in Troy's graphs, the value in a heavier arrow with a slower speed (note that also the speed at the end of its journey is slower compared to a lighter arrow) I can't 😀
Miky, when they lose enough animals, they’ll desire something different.
Troy yer freakin corporate shill! I didn’t see a single a single Viking Cobra bow in the test and I think you know that it shoots twizzlers from the moon at laser speeds. Yer messin with the data LOL
Sir Isaac Newton would be proud.
Momentum coming your way!!!
he would bang his head 😆
Keep the videos coming. My wife's not convinced I need new arrows yet. 😀
@@underdogp229
“Honey, bowhuntig is a cheap sport”
As velocity slows momentum increases. The more mass = more penetration period end of story lol
This too shall be part of a video!!!
if it would be so easy 🤔 ....even momentum (mass x velocity) decreases with decreasing velocity - mass alone does nothing for penetration, it is always the specific pressure / stress (force per surface) at the cutting edge that will facilitate penetration, and there is more than one approach to make this happen....
@@WM-jy9dz
Time to read the ashby reports on mass comparison shooting asiatic Buffalo my friend.
27 year study.
@@WM-jy9dz yes with variables in play. However Mass has more to do with penetration than velocity.
@@brandonpatterson5705 if nothing moves (velocity = zero) there won't be any penetration at all, no matter how big the mass is - it will just be a big chunk of "mass" doing nothing ....😁
For somebody who preaches the unpopular opinion of performance in heavy arrows. Sure is funny seeing you use a way overpriced underperforming Mac product