its crazy to me how these videos only have 7-8-10k views. When you go to ANYONE and talk about archery now, they've heard of the ranch fairy. My uncles, cousins, my local bow shop, everyone knows now. This channel IS changing things keep it up.

They are trying to strawman you by saying 700 or 900 grains all the time. I used to be a skeptic until I started listening. Then I subbed 2 years ago. Thanks Troy for always being authentic.

Momentum as a measurement of penetration potential is absent in the world of ballistics. I’ve been playing with bullets for a long time and all any of us ever thought about was trajectory and KE. Trajectory tells you only how sloppy your range estimation can be, and KE tells you how much energy the projectile is carrying. KE remains the same for a given weight at a given speed, but it’s no guarantee of what really matters and that’s terminal performance. Dr. Ashby proved it over and over again that a purpose built projectile that stays intact will penetrate best because of momentum, KE notwithstanding. This is why a Barnes-type bullet that sheds no weight always penetrates better than a bullet of equal launch weight that comes apart while flying through flesh and bone. Why I never thought to apply what I knew about terminal ballistics to an arrow is something I have no excuse for, but those days are over! Thanks for the outstanding work you and the Ashby Foundation continue to do!

I did email you Troy but I'm saying it here as well. I sought your advice two winters ago. Your advice was spot on. 800 plus grains on a 300 spine. The arrow found its home on a mature bull elk today. This guy is the real deal.

love it. stuck a muley this year. using a higher grain high foc. deer didnt even react to the shot. just stood there and tipped over, rolled right to me

Hell yeah, PHYSICS!!! Wish I had been bow hunting back in college could have done projects of my own. Amazing content and once again can’t argue with results.

I'm glad I found the Dr Ashby's 12 steps and your channel , I've always been a light fast flipper flapper twizzler stick arrow kind guy till I decided to go heavy 682 grains off an 80lb bow chronographed at 249 fps at 6 feet sight taped at 233 fps

The easiest way the bone breaking of either a bullet or an arrow has been explained to me is the example of what you use to cut firewood. You can swing a hatchet extremely fast, but cannot carry enough load to rupture the connecting tissue of the wood. Opposite end of the spectrum is a 12lb maul that carries all of its weight through the wood.

Greetings from Nelson County, Virginia. I just wanted to tell you how much I enjoy watching your videos. I have learned much from doing such. I hold a bachelors and a masters degree in engineering and because of that I really enjoy listening to Dr. Ashby. I love the technical side of the sport, especially arrows in flight. I also like listening to you too Ranch Fairy. You present your funny side in your videos, but you ain’t no dummy. Keep up the great work!

You make your best case when you compare the 516 grain arrow to the 389 & 436 grain arrows at launch and 60 yards. 516 grains is achievable by many archers, while still using 100-125 grain broadheads and can better survive PLAN B scenarios. Keep working on the masses and they will eventually come around. Thanks for the great video and explanation.

Great content. I changed my entire setup last year. I did that after learning from your channel. 32 inch draw 80 lbs draw weight 720 grain arrow weight.

I believe you are on the right track in regards to a momentum value vs just a stated mass of a 650gr arrow is the bone breaking threshold. Stating the obvious, way too many variables with just stating a grain weight....but a momentum value is achievable in various ways by combining velocity AND mass. Keep up the good work (from a nerdy engineer)

These videos are fantastic! As far as I can tell, you folks at the Ashby Foundation are the only ones doing actual research on this subject.

Man I love this and the fact that you are continuing to go deeper with the high speed camera.

I've been waiting for this one. Great proof of concept, and exactly what our sport needs to know. SUPPORT THE ASHBY FOUNDATION!!

Excellent job RF! You the Man.👊

Good stuff and clear explanation Troy!

Awesome content please keep them coming. I’ve learned a great amount from watching your videos and doing my own testing/research. I don’t have a lab radar but im curious about the change in momentum from the change in FOC. Keeping the mass as constant as possible while moving the foc up and down

Good stuff… as usual. Ready for the high speed stuff.

Thanks R.F. for making more magic! ; )

Awesome stuff, thank you!

Whats funny is all the people who drag you through the mud with the bullshit 800 grain arrow talk STILL end up saying exactly what you say. THey just phrase it as "a happy medium" which seems to always entail a 500-550+ grain arrow with high FOC etc etc.. Thanks for your content.

Great vid!! Keep them coming brotha!

Nice job on the details! Can not argue with facts.👍

Thanks for another great informative video 🏹

Hey man love what u do changed my point of view big time. Also i think its hilarious how all the big time sponsored tv hunters take offense to it. Your making them sweat big time haha

This all makes so much sense! I don't understand people that think this doesn't work.

I’m new to archery. This was very informative. Thanks :)

I was wondering, since Dr. Ashby's 650gr bone breaking arrow was shot from a stick bow if I remember correctly: my hypothesis is I think that momentum value is going to yield us a number in the 0.55 to 0.58 considering that he was probably shooting a 650gr arrow at velocity of 150-180fps. It would stand to reason that with our faster more efficient compounds you have incredible success with arrows now in the 500s as you mentioned do your best to get to 550, loaded in the front with perfect arrow flight and structural integrity.

All I can say is I followed the instructions you gave and at 653.7 grains exact and with a magnus buzzcut 4 blade at 70+ yards my setup will knock down freezer queen doe and big buck alike with less than 10 yards of post shot travel

Fan-flippin'-tastic! And glad to see Rob Neilson's test on the Ashby Foundation website. Very enlightening! It's not just about momentum numbers; broadhead design is a critical piece of this puzzle as well. I'd been wondering if I just got the right momentum numbers if everything would sort itself out. It depends on the broadhead. Good stuff!

Seems like the magic number would be 0.60slug ft/S or above. Keep up the good work Troy. Listening to your studies gets me home & out the woods a lot earlier then in the light/fast days. Now, if you could please make a video showing some tips or tricks for getting our arrows & broadhead out of the buried roots without breaking them.

How about a video that shows momentum/KE compared to the trajectory difference of those different weight arrows? This would provide the heaviest arrow for acceptable trajectory data like Ed Ashby promotes. Also curious if you've done any radar speed testing with broadheads on the arrow to see what/if any additional drag is created.

Are you going to do a summary video of speed erosion, ke, and momentum ? Just some take always all combined in one video ? I’m at 619gr and loving it for out to 35 yards. Poor block target doesn’t appreciate it much though haha

Another great video thank u sir

Epiphany moment-arrow effectiveness depends on arrow momentum overcoming target resistance, while cutting vital tissues. The argument about kinetic energy is moot-arrow effectiveness is reduced be the amount of energy transferred to the target. Bow hunters don’t kill animals with kinetic energy, they kill by using a sharp stick to cut vital tissues. Or maybe I’m just dumb and everyone else already figured this out. Either way, keep up the good work.

The elk argument is my favorite. “I need a light arrow to hit the animal at 60 yards, but I’m going to ignore the fact that it may not have enough momentum for lethal penetration.”

RF dropping knowledge again!

Science is fun. The other videos including the ones with The Hunting Public have been even more eye opening. I also recently listened to the podcasts with Aron Snyder and Kifaru Cast as well as the Vortex Nation Podcast. I enjoyed them all and unlike many I take everything in instead of just picking out words that I want to hear. My current setup is around 520 with lighted nocks, but I think I will change the weight distribution around next year.

Good info

The best combo is a large power source with a heavy, structurally sound, projectile. It's just common sense. What gets more complicated is when you have a small power source, as it will limit your effective range, and that's where compromise will be apparent. But for most men shooting that 65+# bow, there's no reason not to experiment if nothing else.

Just for giggles the pro shop that ask me if I was watching that ranch fairy dude posted his 550 grain arrows on Facebook today 😂😂😂

I'm a bit late to the party here but this was really interesting. As a trad guy I'm pretty amazed at the speed and distance that you can get from a compound bow. For me, my bow maybe makes 192 fps on a good shot but I push 650gn and my max range is 20 yards. I'm working on a set of heavier arrows when my new grizzlies arrive. Looking forward to getting everything all tuned up.

Do you have any numbers (or consolidated/combined numbers) on bow draw weight vs arrow weight, and bow noise vs fletching noise on string jump. Is it possible to tune a system so the noise volume or sound frequency won't startle the animal? Also, animal eyes are more tuned to movement than ours and their conscious reflexes are much faster than ours. Do you have any thoughts on them detecting sharp movement from the bow as well as hearing sound? Probably more for deer than pigs.

I would love to see this done with a lever bow. Like an Oneida Phoenix. I think the results would be interesting since everything I read and hear… lever bows shoot heavy arrows the best.

I think I’ve finally digested this three part series. Tough to argue with science. My question is the application, not sure if it’s objective or subjective. What momentum “threshold” is acceptable? Better put (maybe?) would be, what’s the relative difference in the momentum measurement? Is there any appreciable difference in 0.04 slug ft/s? Still trying to balance longer range trajectory complications. (My whitetail setup is a no brainer. 250 spine Apollo’s at 600 or so gr.)

I've been slowly tinkering with my bow and have a great setup now that's shooting great. made the jump to a single bevel grizzly stick Samaria 200g from a 150 g magnus stinger. wasn't expecting so much improvement. but im shooting a 200 spine serius appollo with lighted knocks 100grain half out and a 200 grain single bevel. my bow is a mathews monster chill r with a 31 in draw length and a 75lb draw weight. the KE at launch is somewhere in the 92ftlb range and about 245ft/sec and my arrow at 30 yards blows through both of my targets. had to refletch a few arrows. now I know that my broad heads fly good. needless to say I won't be shooting them very much for practice because I can't afford to loose them lol. Oh yeah my overall arrow weight is 783 grains

If your savvy with automotive power, you can explain it comparing horsepower, torque and engine rpm. I've been closely watching your content since It. Keep up the good work sir, im going to use your math for a build and see if I can take some additional measurements for two or three other guys and their systems and see if there is even more to it.

Good stuff 🖒

I would like to ask a question regarding a trad bow set up, your videos are really great to watch and understand, but most of the time it’s about compound bows/ distance, my questions are shooting a slow longbow and only shooting sub 25 yards are there any disadvantages to a heavy arrow, my set up has been around 500 grains in total but now I know my form is good and I have just set up 28” arrow with 674 grains in total and 28.9 foc arrow flight is perfect can going too heavy be detrimental or is it still the same that even at slower speeds momentum works the same? Regards Wayne

Ranch fairy, what spine is being used on each individual arrow? Specifically the 589gr, 616 gr, and 670 gr arrow?

First: I agree with all the data presented in the video - fully plausible and just representing the mighty physics 👍. Second: I don't agree fully with the conclusion that momentum equals automatically penetration - here the logic to this: I think the following is something even Ashby struggled to get his mind around. Most of the time we overlook that tissue has some kind of flexibility and elasticity. Every time I'm cutting lung for the dog I'm just puzzled how genius mother nature designed this kind of tissue to avoid being cut. It is just so flexible and elastic that it wraps around an even sharp knife and needs quite some force to get cut. There are 2 ways to overcome this: I can slightly freeze it to make it less flexible (works), the second option would be higher speed (hard do to with a knife without cutting the fingers off 😁). Why does higher speed works? ...because of the own inertia of the lung tissue. Elasticity can only work if there is time to move - no time for movement --> no movement at all --> no elasticity. If I minimize the time for elastic tissue to move, cutting becomes much more efficient as e.g. the lung tissue has less time to wrap around my blade thus minimizing the cutting stress due to a larger cutting surface. Therefore, when dealing with elastic matter, momentum doesn't help much, but speed does. (Think about cutting steel with water - it's all about the speed!!!). When shooting an arrow into game, most of the organic matter flexes - the more it flexes before the actual cut, the more energy we lose for stretching the tissue till it breaks - this energy is gone, we can't recover it. The momentum won't help to avoid this flexing and energy losses - speed does as the own inertia of the tissue works here in our favor. The faster the projectile (whether it is a bullet or an arrow), the less chance / time the tissue has to flex, therefore the better the available KE can be used increasing efficiency. Conversely, momentum would just help to stretch more tissue further thus becoming more and more inefficient (try to cut thick lung tissue very slowly without additional slicing movement!). IMO the physics and kinetics of an arrow FLIGHT from the bow to the game / target is pretty much covered, relative easy to predict and relative easy to back up by testing. The big challenge out there is - IMO - what happens AFTER the arrow hit the game, and that is a total different animal. Despite all my internet research I couldn't find any source that revealed data for speed (when we measure the speed we can always calculate the momentum and the KE for a given arrow weight) BEFORE AND AFTER penetrating through a game or specific tissue thus revealing the efficiency of various arrow setups. And exactly this is required to find the optimal combination of speed and momentum for the most lethal arrow.

And this is the exact reason why I donate to Ashby foundation....

Beautiful.

Just finished building my first true "heavy" build this evening. 95 grain Ethics insert/outsert, 150 grain Stinger for a grand total of 570 with 18.5 FOC. Would have gone heavier but with the arrows I have I am on the brittle edge of being underspined. They shoot like darts and are grouping great. My target isn't going to last long however.

Just passin through the city baby

I would like to see the momentum calculated from that 650 grain arrow that Ed determined was bone breaking.

I want to see a static 650 grain arrow shot at various speeds and record the momentum changes. That might unveil the 650 grain momentum curve that Ashby observed in his tests.

Just got out of my college class, learn more here then the indoctrination labs at school

Is .734 slug at the bow over kill? It’s going 250fps so it’s not slow. I’m going to work out to distance. I just got them put together and shot them in the garage on paper. They shot like darts! This is a elk set up fyi 675gn total weight

Any future testing say for traditional bow say graphed from 10 and 20 yards... i know it will show most likley same results but adding a trad bow to the mix would be interesting to see.

Thank you for continuing to share the truth about heavy arrows. You're catching a lot of heat from other folks.....ya know....the self proclaimed Professional bowhunters on TV. I was really surprised sell out Wadell had some negative things to say about you. Guess Walmart won't carry Adult Arrows so he can't get paid. I really think those guys are just late to the party and don't have the balls to admit when they're wrong. Again, thanks for making sense.

My money is on momentum every time old son! Great illustration

fantastic video and info as always RF! hey has anyone ever told you that you kinda look like james hetfield? yall could be brothers lmao

Just thought I'd say that I really enjoyed your talk with Aron Snyder on the Kifaru cast. I knew yall would have a lot more in common than he thought. Especially the way he had been talking on Elk Shape and such. I think it will help clear the air for some that just look at the surface level and see where you really stand on things. Also I wonder at what point is there diminishing returns or where is starts to flat line for the momentum. It has to be up there at a completely unrealistic arrow weight like 1500 grains or something

Yup :)

i noticed the videos that reference heavy arrows talk about he trajectory of the arrow and they dont want to be arching to ge tto the target. do you plan on showing the arrow trajectory comparisons? i would find that to be a fun video to watch. and i woul do it my self but i have only been doing archery for almost 2 years and never gone to do anything past 35 yards.

Ballistics of firearm projectiles is discussed in three categories: internal, external, and terminal. That is also a good way to think about archery. Internal ballistics deals with converting the stored energy of the bow or powder into the projectile while in or on the machine (bow/gun), external ballistics deals with the projectile in flight to the target, and terminal ballistics is what happens once the projectile reaches the target. I think your data/charts are showing the efficiency advantage of heavy arrows for the first two. More energy and momentum is being stored in the heavier arrow at launch than in the lighter arrows, so that shows the efficiency advantage in internal ballistics. Then the increased velocity erosion during flight (of lighter arrows over heavier arrows) while mass stays the same demonstrates the efficiency of heavier arrows in flight. I guess penetration demonstrate the efficiency advantage of heavier arrows upon impact. I guess the trajectory counter to all of this is that we still must hit what we are aiming at. In firearms a hit with a 22lr is more deadly than a miss with a 50BMG.

You are right about this. Maybe the people who shoot ballistic gel should test shoot at 60 yards their light twizler stick to a 650gr set up

FOC fear of change.

Hell yeah

Are you connected with @SmarterEveryDay?

I would love to see you take this one step farther and analyze the arrow trajectory. The reason people want lighter/faster is flat trajectory. I personally have moved up from 405 to 470 with my 60# bow. The trajectory is not as bad at 60 yards as expected it to be.

Hey Troy!! Seriously, look at graph shift at 589grain arrow. Interesting?!

High speed camera of you shooting your test subjects (a.k.a. Pigs) would be great to see.

Exactly why you don’t generally shoot elk with 90 grain bullets. I’m somewhat new to archery hunting but have been overly obsessed with rifle hunting, shooting, load development , and gunsmithing for several decades now. Heavy bullets may start out slower but they carry much more energy, momentum, and penetration down range. Actually at a certain range a heavy for caliber bullet will pass a light offering in velocity as well due to efficiency. I wonder if there is a point where an arrow would be behave in the same manner.

Is there another way to quantify slug feet per second? A change of .2 might be alot in the field but on paper it doesn't represent a worthy change very well for most people.

If the media the arrow passes through is denser deer body or pig body? How much faster are the light arrows momentum and overall energy degrading compared to a heavy arrow

Is this data available in excel anywhere?

I agree with the statements made in the video, but momentum is a curve. At some point, depending upon mass and velocity, momentum begins to decrease based upon velocity drop due to mass. For a modern bow at ~70lb draw weight that starts to happen around the 620-670 grain data point (kudos to Dr, Ashby). Your video does not show that decrease, and could lead some to believe that momentum is ever increasing based upon your chart, but that clearly isn't true since momentum is simply mass times velocity. With that said, Dr. Ashby also said that an arrow that derives the majority of its momentum from mass instead of velocity will penetrate better. In other words, if both arrows have a momentum of 0.6071, but one is 805 grains moving at 170 FPS and the other is 510 grains moving at 268 FPS, the 805 should penetrate better. This is a study I performed with my Mathews V3X 29 at a 29 inch draw pulling 72.1 lbs. The point of this comment is to simply recognize that heavy is always better...to a point. For instance, the aforementioned bow produces 0.6344 ft/lbs sec with a 600 grain arrow and only 0.6071 with an 805 grain arrow, with a dramatic speed and trajectory issue of losing 68 FPS, the archer should obviously choose the 600 grain arrow. Long story short, folks should do the math to maximize the lethality of their individual setup. It is definitely not a one size fits all. Love the video though, keep up the good work!

Is there a total arrow weight that is to high or that you think is over kill? Have you thought about testing a 2,000-3,000 grain arrow on one of your ranch test specimens?

I'm shooting a vertix, 75lbs, 301fps, 451gn arrow. Have never had any issues with penetration. I also shoot a lot at 100+ yards and this set up is awesome

Read the Cape Buffalo case study...wow. 39# bow with superior head did better that the 82# bow with 1100+ gr. total weight with a lesser head. Insane!

You and the Rocket Man need to come up with a uniform medium that can act as a barrier to penetration and be used to confirm the bone-breaking threshold. Some high-speed camera work could show how lighter set ups wither under the test. Good luck

Funny how you see those guys on hunting channel shoot whitetail and have over half the arrow sticking out of deer shooting high poundage bows

Thanks Troy & Darrel keep educating the archery world. I see a minimum momentum number for each kind of game. you wouldnt shoot bird shot at a deer why would you shoot twizzler loads at a Elk? While that 400gr arrow might work in the south on 120lb deer, turkey, & pronghorn, everything else is going to require high brass loads.

Science!

Did you see the bowmar bow hunts in Africa?

Your scientific approach to testing is refreshing and appreciated. I have been bow hunting for over 25 years. Early on it became very clear to me that I was passing on more 50+ yard opportunities than I was getting below 50 yards. To improve my chances at harvesting game I decided it was imperative to become proficient at greater distances. I have hunted the last 15 years with a sub 400 grain arrow and have taken 3 bull moose between 50 and 84 yards (all 3 complete penetration). I have taken numerous mule deer between 50 and 70 yards (all complete penetration). I shoot the light arrow for improved trajectory and have never had a problem with penetration because I pay particular attention to the other variables you mention. Perfect arrow flight, a broadhead with great structural integrity, and lots of energy from my kinetic energy machine which gives me adequate momentum even with a lighter arrow. I will be experimenting in the off season with higher FOC and a heavier arrow to see if I can find a better balance of momentum and trajectory like Mr. Ashby suggests. Keep up the good work!

Just curious how you combat all the backlash guys spew about arrow speed, I personally don't care if my arrow flys at 280fps at 20 yards vs 340. But there's so many folks out there trashing us that follow Dr. Ashby's studies and they only want to argue how slow our arrows are.

KE is a messenger. Momentum is the massage. HeHe >------->

Ok, this is great stuff, but the next test should be to measure the flinch of an animal, and see what speed you really need to make an ethical shot at 30 yards, 60 yards etc.

science!

Why can’t u use accelerometers to measure impact? Possibly use blunt tips and see what the difference is in force. Maybe that’s a dumb idea.

So in Laymans term you have a smart car and a Cadillac both traveling at 60 mph when they hit something the Cadillac is going to do more damage because it has more weight behind it even though they both are traveling the same speed ??? Sorry for the example just trying to understand it in simple terms.

I'd say the distance argument they make against heavy arrows is. That if you don't range perfectly your arrow drop per yard is so high you lose accuracy. High speed arrow has less drop at distance.

Momentum=transferable inertia

💪🏽🇺🇸🏹

I always put it this way, if you throw a ping pong ball, and a golf ball at the same speed (or close to the same speed) at your drywall in your home, which one is gonna go through the wall? No-one ever gets the answer wrong. Or, if I throw a ping pong ball at you as hard as I can, and then a golf ball, which one are you gonna try and duck and cover from? No-one gets the answer wrong. Heavier projectile will hurt more when it hits, its harder to slow down....

I know you probably hear this alot and are getting sick of it. I know Ed's study is with a stick bow. What does that 650 grain arrow going 190 fps momentum equate to on a modern day set up. Would this equate to 495 grains at 285 fps. I am just throwing random numbers out there. Also I plan on getting a lab radar and will be more and happy to send you my data.