BOWHUNTING SCIENCE KNOWLEDGE BOMBS with IRONWILL BILL

[@ApexPredatorOutdoors]

Science is science. One thing not many talk about is that an increase in FOC will help as well with Impact paradox. The impact paradox will effect how much of that energy that reached the target actually gets delivered through to the animal via the broadhead.

[@SouthMississippiSalt]

So basically he is saying what that crazy dude , whats his name , O yea , Ranch Fairy has been saying for a while now . But he is doing it in a class room setting and not hurting flat bill hat guys feelings .... haha .... This is another good video , whatever it takes to get people shooting good .

[@HickLif3]

Sometimes it takes a different person to finally get the same point through to people

[@bmills231]

It's funny, because not one time did I hear him speak about 350grain arrows like Ranch Fairy has, nor did I hear him mention the need for 650gr+ bone splitting plan B arrows, again like Ranch fairy has. What Bill talks about is what I'd expect from an engineer, wildly enough he doesn't mention a particular weight... sounds like a smart guy to me! A 500 grain arrow isn't vastly different to a 650 grain arrow when comparing momentum. Shoot what you want but make sure its something that has structural integrity and is properly spined out of a well tuned bow and a sharp, durable broadhead. End of discussion.

[@jesse4530]

I knew someone would praise RF and someone would diss him. Lol They do talk about alot of similar things. As heavy of a setup as you can with acceptable trajectories, the center of pressure and FOC, tuned bow. RF is like a comedian talking science and this guy is like a math teacher. Sometimes it takes a different personality for a person to listen.

[@alexgrier9869]

I could listen to Bill talk archery all day. He should put out some sort of book of all of the tests and results he has done throughout the years.

[@steven_farmer89]

Another great guest instructor, dropping knowledge bombs. Thank you, I believe this is the year I'm filling my tag; keep up the great work.

[@kevinburrall]

As a science teacher and a bow hunter…I approve! 👍👍

[@BoxofRoxRacing]

Ironwill 125gr heads are on the front end of my arrows this year, really hope I can drop one in an elk.

[@chadcoxthehunterchadcox8252]

Trying the 125 single bevel iron wills this year. Excited

[@sgtcaco]

Great chat, thank you mate.

[@ElkShape]

Glad you enjoyed it

[@rileyoneil2978]

Day 6, 275 up front (Bishop single bevel), 676 total, dialed in up to 80 yards and it hits like a tank. Cant wait for the season.

[@RobertKearl-Outdoor-Adventures]

Sirius Vulcan 286 up front grizzly stik samurai overkill single bevel out front 682 grains . I'm hoping to dial it into 90 to 95 yds think 100 and I'll smack my sight housing

[@rileyoneil2978]

@@RobertKearl-Outdoor-Adventures Love it!

[@RobertKearl-Outdoor-Adventures]

@@rileyoneil2978 I ordered some 200 and 315 grain field points to play around with over the summer and see if I can't resolve my left of center issue I'm having atm

[@scottposey2996]

For you guys shooting really heavy at long distances what sight are you using? Fixed pin or adjustable?

[@roblayman6630]

I can just see John Dudley rolling his eyes now !

[@Mackahroney]

Heavy, high FOC. Have been shooting my 515 grain(not heavy at all) with 19% foc and have shot straight at 60 yards. Will try out to 100 once in back at the range

[@brianr.collier5071]

Just what I needed as I prepare for September!

[@pippencreekproductions]

Man I wish I could’ve had Iron Will Bill teach my dynamics class in college. Would’ve been SO much more fun. 🏹

[@coreykolenosky5974]

The best vane is Feathers.....

[@richarddean3154]

Great video. Bill is almost as smart as I am :) Great explanation regarding the balance point and how the back portion of the arrow acts as a counter to the front portion. Great job

[@ElkShape]

Bill is OG

[@kylemarkum2872]

Is the full video behind the pay wall on the website? Not an elk hunter (yet) but I’d pay to listen to the rest of the video and other similar videos. As an engineer, I like learning information from this perspective.

[@ElkShape]

yessir.. it's at theelkcollective.com

[@DavidGonzalez-ek3zh]

He has mentioned in other videos that the sharpness of his Iron Will heads is paramount for better penetration especially for lower lb bow set up

[@Diplomatt-k4z]

Great presentation - I have so many more questions for him.

[@timl8302]

In archery, Momentum = M*V/225,400

[@bradhubbard9876]

Will his shop and/or Spokane Valley do full arrow builds with his broadheads and ship out of state?

[@ElkShape]

Spokane Valley Archery will!

[@akduckfever]

Wow that intro music I was waiting for someone to say mortal kombat

[@andrewmiller7095]

Are you going to do elk szn again like last year. I really enjoyed it.

[@ElkShape]

oh yeah something like that! BEAR SZN first though ! - TC

[@andrewmiller7095]

Yea buddy I’m pumped for it

[@greghaskell1676]

Compounds have way more kinetic energy than recurves, especially in heavier weights. I still say a single bevel 21/2 length to width is the best for penetration. The iron will,shown will not penetrate anywhere near as well as as a 21/2 to 1 head!!!!!!

[@WMBCS]

Single bevel =single drop blood trails lol

[@droptine04]

😂😂😂 that's funny shit right there.

[@DigtoDef]

Great job, Bill

[@jacobbrazell8684]

Some day I’ll buy some… just so damn expensive.

[@QcConnection]

Bible. Right there.

[@jordang94]

It takes a big rig longer to slow down than a little car thats how i look at it . ABT !!

[@mattlounders2940]

This guy basically says everything ranch fairy and ed ashby tell you.

[@liammacpherson3616]

The vid they made trying to talk down the Ashby report they don’t realize that their perfect flying arrow was an arrow that is still hitting all the factors that the ranch fairy talks about.

[@lymanclark5537]

He danced all around the high FOC without saying Ranch Fairy or Dr. Ashby. He quickly said its hard to get high FOC and have long range trajectory but everything he says is endorsing a higher FOC. It again comes down to the fact that archery is not meant to be a long range weapon . Learn to hunt and get close.

[@RobertKearl-Outdoor-Adventures]

Im playing with a 682 grain arrow 17% foc but I'm shooting 80lbs and getting 244 fps out of this set up .

[@liammacpherson3616]

@@RobertKearl-Outdoor-Adventures like I’m not even arguing for heavy foc. But like if you COULD shoot an arrow that’s heavier, why wouldn’t you make sense to me

[@RobertKearl-Outdoor-Adventures]

@@liammacpherson3616 True I've almost always shot heavy arrows with the exception of my pse that's shooting 375 grain arrows lightest I'll go

[@steammaker48]

Very deep

[@johnkertzman3223]

I killed my first animal with a bow in 1991 and I've been bow hunting every year since! I tell you the thing I think I've learned in that time is always try to use a stiff spined arrow as you can for your draw weight. I've always gotten better penetration with a stiff arrow as compared to one that's light in spine!

[@sgtcaco]

Hi mate , could I ask you some questions about my set as you seem very knowledgeable. I’m building my first hunting arrow. My current draw weight is 55lb but in 1 month I will be at 60lb. I have chosen a 350 arrow. Is this going to be ok? I have not bought my broad head yet but I am thinking of using a 100g single bevel but use a 75g insert. Do you think this will be ok? I will be using 2 inch fletch at 15mm height.

[@sgtcaco]

I meant 340 arrow shaft.

[@sgtcaco]

Also shaft length is 30inch as I have a 19.5 draw length so I can not go any shorter.

[@frosty0419]

I can see our ancestors sitting around the camp fire thousands of years ago having this conversation before they killed Buffalo with their Osage bows on the big hunt. 😂

[@Bent-rAgE-559]

Good info 👍

[@rackshackarchery9966]

Awesome content

[@Farmersforever1993]

Greta video and knowledge. If it’s hard for you to follow along or understand then you obviously didn’t pay close attention bc the repeat parts are where this was edited and pieced together.

[@brpnw4r94]

"What's the "best" arrow to kill a Elk"? 12k videos on YT explain just that. I'd be asleep in the first row listening to this dude.

[@Sapper_Rage]

Stay awake, he's giving valuable information.

[@jatollar]

I think he drew unsupported subjective conclusions from objective physics equations. Some example calculations using light and heavy arrows are needed to make conclusions. If I wasn’t so rusty, I think I could possibly come up with some graphs to show crossover points etc. I’ll go through an example using arrow weights I think most would consider to be light and heavy after addressing the equations. Energy and work are not the same. The work done on an object is equal to the CHANGE in the kinetic energy of an object. Like he said, the bow is doing work on the arrow and adding kinetic energy to it. A bow has the same potential energy at full draw, and the same “static” force curve, which is the force measured at specific distances when the string isn’t moving. It will impart different kinetic energy on different arrows because different weight arrows have different inertia which is an objects resistance to change in momentum and because of the different impulse (average force * delta time) the bow generates on different arrows. A lighter arrow will have more energy because it will accelerate faster because of the V^2 (Velocity squared) component in kinetic energy. He mentioned drag also has a V^2 component, but drag is an aerodynamic force that slows and object down and velocity is one variable of four if I remember correctly, whereas velocity is one of two variables in kinetic energy. I’ll show that he is incorrect when he assumes that a faster arrow will end up slower than a heavier arrow, there are simply too many cases where that will not be the case, certainly not at hunting distances and specifically every case where the slower arrow is in the dirt or in a tree branch above the line of sight when the faster arrow is still in the air because of it’s lower arc. I digress, the first equation should be work-energy: F * d = (1/2)*m*(Delta V)^2 The second equation shows how impulse (force over time) changes momentum due to the change in velocity. As mentioned above, a lighter arrow will experience greater change in velocity or acceleration. the change in velocity. With a lighter arrow, the average force the bow generates acts over less time, ie greater impulse. The equation should be: F * Delta T = m * Delta V The real point I want to make is that whether heavy or light is better depends on a lot of factors. I agree the important factor is momentum because arrows are a cutting tool and hunters want pass throughs which by definition means they want to conserve the arrows kinetic energy and momentum: Kinetic energy = (1/2)mv^2 Momentum = mv Comparing two arrows 400 gr and 600gr I threw in some numbers into a free velocity calculator using a 28” draw, 342 ft/s IBO (31” V3 bow spec) and got the following estimated velocities: (www.westernwhitetail.com/tools/archery/arrow-speed-calculator/) 400 gr, 306 ft/s 600 gr, 240 ft/s The 400 gr arrow has 66 ft/s or 28% higher velocity, if being able to hit your target, we’ll see this is a huge advantage at all hunting distances shortly. How much additional momentum are we getting? Momentum = mass multiplied by velocity = mV I omitted some conversions for the sake of clarity, “slug” is a funny term for mass using imperial or “English” units ie foot, pound etc. The momentum for each arrow is calculated to be: 400 gr arrow = 0.543 slug*ft/s 600 gr arrow = 0.639 slug*ft/s The 600 gr arrow has 0.096 slug*ft/s or 18% more momentum to start. To put this in context, a bullet is clearly better than an arrow at smashing bone and a 150 gr 30 caliber round traveling 2,800 ft/s has approximately 1.863 slug*ft/s momentum. The heavy arrow advantage of 0.096 slug*ft/s is approximately 5% of that. What about trajectory? It is true that faster objects slow down “faster” than slow objects, but they already have a velocity advantage which means they take less time to reach the target or “drop” at a significantly slower rate. I used a free ballistics calculator to calculate the velocity and drops. www.bestcrossbowsource.com/crossbow-arrow-ballistics-calculator I was shocked. The lighter arrow is calculated to be faster at every distance! In fact, at 70 yards the 400 gr arrow is calculated to be 41 feet per seconds faster than the initial velocity of the heavy arrow! Between 10-20 yards the 400 grain arrow drops 5 inches and the 600 gr arrow drops 10 inches! You better nail your ranging even at this close distance if you’re shooting a heavy arrow. Between 20-30 yards the 400 grain arrow drops 11 inches and the 600 gr arrow drops 16 inches! Between 30-40 yards the 400 grain arrow drops 14 inches and the 600 gr arrow drops 21 inches! Between 40-50 yards the 400 grain arrow drops 18 inches and the 600 gr arrow drops 29 inches! The lighter arrow offers incredible forgiveness to ranging errors so you are far more likely to hit where you are aiming even with some ranging error. Wind drift, we could go over drag, but I’m happy to simply point out that pros all use fast, light arrows outdoors. I’m willing to bet more hunters miss because of ranging errors than anything else and the heavy arrow drops 16 inches between 20-30 yards, light arrows get pass throughs too, but what we really need to settle the debate is the minimum momentum needed. There’s probably a sweet spot that is completely dependent on the target.

[@whalescience8831]

Very well put. I was thinking the same while watching this but was too lazy to do the math myself.

[@recurrenTopology]

Your comment makes a couple of errors: "A lighter arrow will have more energy because it will accelerate faster because of the V^2 (Velocity squared) component in kinetic energy"- A lighter arrow will have more velocity, but this will not result in more energy than a heavier arrow. When fired, a bow converts its potential energy primarily into the following: 1) kinetic energy of the arrow; 2) kinetic energy of the bow (largely the movement of the arms, string, and cams); 3) friction. Assuming arrow weight has a marginal impact on friction, we can focus our concern on the first two. The faster the arrow is launched, the faster the components of the bow will be moving at launch, therefore the bow's kinetic energy will be higher, leaving less kinetic energy for the arrow. For this reason, in general with all else being equal, heavy arrows will have a slightly higher kinetic energy (despite a lower velocity) than lighter arrows from the same bow. It should be noted that the arrow-velocity calculator you linked to does not demonstrate this effect because it has linearized the velocity equation around the 350 grain arrow weight. This will work well enough for weights close to that weight, but the approximation will break down for weights with a greater deviation. It mentions in the assumptions that it treats velocity as linearly inversely proportional to change in arrow weight, when instead velocity should be roughly proportional to the square root of the reciprocal of arrow weight. "I’ll show that he is incorrect when he assumes that a faster arrow will end up slower than a heavier arrow..."- I think you misunderstand his point here. It's not that heavy arrows will be faster than light arrows, it is that light arrows will lose more kinetic energy over a given distance than heavy arrows with equal initial energy. The difference in drag coefficient and cross sectional area between a heavy arrow and a light arrow will be minimal to non-existent, so the primary factor influencing drag force will be velocity. Aerodynamic drag force is proportional to velocity squared, so an arrow traveling faster with equal drag coefficient and cross sectional area will lose more energy for a given distance than a slower arrow. Since heavy arrows move more slowly for a given initial kinetic energy, they will retain more of this kinetic energy on target than a lighter faster arrow with equivalent initial potential energy. The caveat to this is when the trajectory becomes an extreme arc such that the heavy arrow would have to take a significantly longer path to the target, but such an instance is well outside bow hunting parameters, so the above effect is far more pertinent. Your subsequent points about trajectory are all correct.

[@eddieweightman7864]

Exact

[@garrettrowe7917]

Dude is saying everything that I’ve said and got railed for it in this channel. In other words 1.structural integrity 2.perfect arrow flight Etc, etc lol

[@rileyoneil2978]

Light arrow guys slowly becoming extinct.

[@ElkShape]

Shoot enough weight to support your penetration/flight goals - TC

[@rileyoneil2978]

@@ElkShape Penetration goals? Shouldn't this be the same for every hunter of a specific species, full pass through every time...? Lethality should not be a preference.

[@allthingsloveless]

@@ElkShape I'd go far as to say shoot enough mass for the game you're targeting in the environment that you're chasing the game in.

[@andysmith8295]

@@rileyoneil2978 There is a lot of variables which influence a hunting arrow. Remember that not everyone is shooting the same game at the same distances. Also, not everyone is shooting 30" and 70 lbs.

[@rileyoneil2978]

@@andysmith8295 Absolutely, but always look to maximize lethality out of respect to the animal.