Who has or is hunting with a 650 grain or higher broadhead out of a 45 lb or lighter bow?

If so how has it been working for you?

Why so heavy of arrow?

If you shoot heavy enough of an arrow, you can drop it into the deer from a tree stand.

I have been using a 550gr as well as 600gr arrow out of my 47# Black Widow. The combination works for me since I very rarely shoot over 20 yards at game animals

According to Ashby's studies 650 grain is the weight it takes to burst open heavy bone and still make a clean kill. As Ashby says this is the things went wrong but still got the animal setup.

Just curious if people are shooting that out of lighter bows.

I currently shoot a 43# PLV with a 460 grain arrow. I shot a friends 630 grain arrow and was surprised how little difference there was in trajectory out to 30 yards.

From 45-65# I have arrows that are 9-10 gpp.

Never heavier...cannot see why.

Heavy is good...within reason,as long as you don't have lawn dart trajectory! Also quiets they bow down nicely.

Ash arrows out of a #46 Hill style longbow. They hit hard.

Ashby's studies were about big, dangerous African game...not thin skinned whitetails or other North American game. Most of my deer kills are either pass through shots or at least complete penetration of the broadhead. I only had one that didn't have two holes on the shot and it was quartering away and into opposite shoulder. 650 grains at 45# is getting close to the point of diminishing returns, depending of course on the bow's dynamics.

I have always used the thought process of 8 to 10 grains per pound to be a very good suggestion. Most of my arrows are 10 to 11 grains per pound but it varies as well.

A heavy bow (over 60lbs) shooting and arrow of 1000gr, or even more, can still have the broadhead stick in a bone. 650gr is not a magical number. Bursting bones????? That is rifle thing.

“According to Ashby's studies 650 grain is the weight it takes to burst open heavy bone and still make a clean kill.”

Are you familiar with the concept of “Necessary And Sufficient”?

650 MAY be Necessary, but it’s probably not Sufficient.

Those studies (I’m prepared to assume!) were conducted using stout bows meant to be used to take heavy African Plains Game; and a #45 is a #45. Entirely accurate by all reports, but pretty unlikely to bail you out of a jam if you hit something that you really shouldn’t.

Personally, I would think it would be more likely to cause a problem due to a looping trajectory than to solve one for you by blowing through anything hard.

raghorn X2 bone busting myths

Ive used bows from 40-42# to harvest whitetail--- the heaviest arrow i used was just over 13 gpp (490 grains) at my draw. I usually stick to 10-11 grains per pound and as long as i hit them in the ribcage i get decent penetration. I found that the heavier arrow 13+ gpp dropped like a rock after 20 yards and was really running out of steam at 30. Your bow must handle heavier arrows better. Check out Jinksters YouTube videos using bows that really perform w heavy arrows. I'll stick to between 10-11 gpp as i alternate between bows and hunting and 3d-- it keeps the gaps the same and since I'm easily confused, thats a good thing.

Actually Ashby's Natal study , the first, was antelope and warthog size animals. I think it was four years long and was done to see if bowhunting was a viable method of killing to allow set seasons.

He started shooting bigger and bigger animals because there was only so many measurable inches in the others to gauge penetration.

The Dr. explains the bone breaking results in his tests. Results from thousands of shots. If you don't care to read the information, fine, but shouldn't be misquoting it based on some second hand hearsay.

He also did some personal tests with different types of archery equipment. Lots of bows peak efficiency is found in the 12-14 gpp range. The myth that arrows "run out of steam" or "drop like a rock" is easily debunked. Any archery ballistic calculator will do it, or shooting. Some recurves with older limbs or design may not be more efficient past 10 gpp but arrows do not just stop in midair like some cartoon and hit the ground.

I was with CW on Sunday and watched that 650 grain arrow make it all the way to the 30 yd. butt. It might have been a few inches below the impact of the 460 gr. arrow but not much.

https://player.fm/series/kifarucast-2362284/dr-ed-ashby

ashby shot cape buffalos with 45lb bow and 650 gr arrows into bone and about 50% of those got through the bone and then 12” of penetration. thats impressive to say the least. the arrow mass was the most important and significant factor for penetration in the study (from my memory). the other factors like foc and broahead type had some but less effect. he has all the factors paratoed in one of the reports. its certainly the most thorough piece of work on penetration that will probably ever be done. its certainly worth reviewing and considering in hunting set up especially for lighter bows. i personally would probably not like an arrow that heavy on a light rig but i also wouldnt be hunting really heavy game with one that light

"650 MAY be Necessary, but it’s probably not Sufficient" - I'm pretty sure that is backwards.

"ashby shot cape buffalos with 45lb bow and 650 gr arrows into bone and about 50% of those got through the bone and then 12” of penetration. thats impressive..." - What was the result of the other 50%? It's not that impressive if it only works half the time. I'm just asking, I don't have any bias for or against 650 grains at 45lbs.

I think GF meant "EFFICIENT"

why not 650 if its good enough for buffalo .then plenty sufficient for deer. i'd rather be on the heavy side

low country, the other 50% didnt get through. i dont recall the exact numbers but until you hit that 630-650 gr mass the results were very few or no arrows getting through the bone. this was stictly acedemic imo as obviously you shouldnt be hunting buff with a 45lb rig. with heavier set ups you get much higher breakthrough % , as you would expect. point is that mass, >630gr i think, was the biggest factor on getting through bone followed by broadhead type (i memory serves)

Well how about 629, or 635. Likely wouldn't work. Just FYI, 100 grain tips on arrows under 500 grains will work just fine. It's the numbers thing again. We ain't happy unless there is a magic number to apply. How on earth did we ever survive to discuss such goofy things.

By the way, how far an arrow can fly accurately is based on the shooter and the angle at release. A 45# bow can shoot a 650 grain arrow a long distance, and easily out to fifty or sixty yards. Just not as fast as a 450 grain arrow, which by the way will do quite an efficient job as well.

I think you are missing the point George. Nobody is arguing that you can't take deer with a lighter arrow. I've killed deer with 350 grain arrows.

The 650 grains as I said earlier is the setup that when things go wrong and you hit heavy bone you have a better chance of recovery.

I've always been in the camp that I was not willing to give up the speed. After actually shooting a heavy arrow I no longer am worried about that for my hunting setup.

The original post was about who has tried this and what their results were. I figured it would turn this way....

no body says you cant kill with a 450gr arrow from 45 lb of course you can but youll be having problems shooting through heavy bone. more than you would with the extra mass. the 650ish is where you start to get through heavy bone with consistent results. read the reports its a revealing study and its free. it puts some actually quantitive data on stuff that has mostly been conjecture for a long time. should you change your set up based on the data? maybe, idk? i still shoot 500-570gr

I've seen the effectiveness of 45# 650 grain arrows on large bull elk using a grizzly single bevel broadhead. The kills were at 20 yards or less. One of the benifits of heavier arrows are they are easier to see in flight. This can benefit in accuracy and in seeing where the arrow hits.

tradmt, and many were the big game animals taken with pre Ashby test equipment, so I tend to look at the entire picture, as well as my own experience...and that of my buds. Yeah, we are old guys, and maybe a bit hardheaded, but we also know the best indicator of future performance, is past performance. No fussing about Fred's choices, but they aren't mine and mine still work.

I never have, unless it's one of the big hook recurves, you're going to have to shoot it like a mortar!

A 650 grain arrow impacting a 30 yard target just a few inches lower then a 460 grain arrow... I want that bow!! Several guys shooting the 650 grain Grizzlystik says their arrows impact 11" lower at 30 yards then their almost 500 grain arrows.... My 650 grain Grizzlystiks impact 4" lower then my 460 grain arrows at 20 yards. Shooting machines take out the human action of pulling a lil farther or holding a lil higher...

We are talking momentum, and when arrow speed drops off, the momentum doesn't increase, it drops off as well. As for the Ashby study, didn't he use arrows that weren't tuned from the bow he used? I know he used arrows from guys that were around to shoot buffalo with. I'm pretty sure he did... And from his personal bows, weren't they over 70#? I know in one test they used a 36# Elite...ummm Not saying anything about the Ashby study, but I'd rather build an arrow with around 16% to 18% and 10 grains per pound then try to bare shaft tune a 650 grain arrow., I'm plating with a lil 48# recurve now, now it's speed with 440 grain arrows, would hate to see it with a 650 grain arrow...

Well, I guess you know it’s an “interesting” thread when you see yourself being “it out of context!

So just to clear up a few ambiguities…

My sense is that a 650 grain arrow might be the benchmark at which Ashby arrived for “necessary”, but the mass rating itself is not SUFFICIENT.

As an analogy… My phone says Von Miller weighs about #250. There are probably millions of men in this country who weigh about 250 pounds. Not very many of them will hit you as hard as Von Miller under a full head of steam.

You can’t just put your arrow on a weight-gain program and expect that to turn it into a battering ram. That would be like “getting in shape” by becoming a couch- potato and gaining #50.

Not gonna happen.

JMO, shoot the draw weight that gives you the best balance of horsepower and accuracy, and shoot the arrow that gives you the best tune and the best balance of mass and trajectory within your self-imposed range limit. But don’t hobble your welterweight bow with a Sumo-class payload thinking that the Physics Fairy is somehow going to bail you out on an unfortunate shot placement.

well put gf. i personally cant see myself running 650 gr arrows from a 45lb rig. oh but now my compulsive side wants to try it just to see lol if i try it ill post something lol

What shoots most accurately? I could be wrong but I suspect that 14.44 gpp ain't it...

Actually for most hunting shots that bow/arrow combination would be just fine. The trajectory is such that shots from 0 - 20 yards would require very little if any elevation calculation.

"What shoots most accurately? I could be wrong but I suspect that 14.44 gpp ain't it..."

If I am remembering right a lot of 300 rounds are shot with #30-ish bows and +500gr arrows full length and I've seen some 280s / 300. Interesting how the mind works when the "hunting" is the subject. My main concern would be to have a decent speed to hit the target when it arrives at 20 yards, not the accuracy of the set-up.

What’s more important than the hazy recollection that “a lot” of 300 rounds are shot with 16-17 GPP arevthe ABSOLUTE FACTS that A) ALL 300 rounds are shot at exactly the same, KNOWN range for EVERY shot and that the targets NEVER, EVER move, shy of an earthquake, and B) that trajectory/elevation is more of an accuracy issue for archers than Windage.

Once you introduce estimated range and moving targets, a little zip ain’t all bad.

I sure wouldn’t want to stand in front of a 650 grain arrow coming off of a #45.... but if I had to choose between a 650 and a 400, I like my chances of jumping out of the way a lot better with the overweight shaft.

I have used 1/4" rope inside 2016 Legecy shafts, just to see how they would shoot out of my 44lb bows [ 1 recurve and 1 longbow ] and I was actually surprised at how well they shot. Total arrow weight was 640 gr. Made 4 hunting arrows with STOS broadheads and killed a nice white-tail buck with one, a 10 yd shot from a tree stand and a pass-though.

Most of these discussions make good entertainment but that's about it.

There is a knack to killing deer with a stickbow, once you have it, you'll soon figure out the arrow or the bow isn't what got you there.

and you'll soon enough realize the old 9-11 gpp works just fine.

“There is a knack to killing deer with a stickbow, once you have it, you'll soon figure out the arrow or the bow isn't what got you there.”

I was thinking about that just the other day while reading one of the endless Mechanical Broadhead threads on BowSite. Seems like those guys have a deep- seated league to praise the equipment that they’ve chosen; maybe it’s because so much of it is so damn expensive, although I doubt that many of them have as much tied up in high-end bows as a lot of Tradguys do.

But it’s a funny thing; they make a good shot and can’t say enough good about the Broadhead, as if it’s a miracle that it did exactly what it’s supposed to do.

???

A heavy arrow will work fine on a good hit. Who knew?

I didn't read this word for word, but there's an important aspect of Ed Ashby's studies left out...he was testing single bevel broadheads.

That adds a new dimension to bone splitting capabilities.

I learned some interesting things listening to the Kifaru podcast with Ashby.

One of these was that we all know what has worked well for us, but we don't know what didn't work.

How many threads are there that go... Hit looked good but did not recover animal. We chalk it up to things happen.

When Ashby did the study's on thousands of animals they have a rifle with them and if there was any suspicion that it was not a good shot the rifleman would drop the animal. They would then autopsy the animal, even as far as injecting die into intestines etc to better see the wound channel. He knows not only what does work nut what does not.

I’ve shot 650 grains from a 45#@28” bow for 15 years. Killed about 20 deer, 7 hogs and a bear with that set up. Use 225 grain Tuffhead on spruce arrows.

No penetration problems, and I don’t shoot past 20 yards anyway. Super quiet. Shot completely through a big, tough old boar last year through both shields.

What accounts for the scalloped edge of the cut on that boar???

The sawing action of the knife cut. You can see where the broad head penetrated about the center area.

Impressive Okaw, I think you pretty much "dropped the mic" on this thread.

Bazinga!

So the streak of mud & blood is the path of the head on its way in???

I think people are interpreting the pic as all Broadhead damage (which would be mighty impressive, if it were), but I’m trying to envision what the BH had to get through, and also wondering how much further the arrow went...

But you did say it penetrated both shields.... which is full penetration, IMHO....

Is the shield a layer of gristle under that nice, white fat? Or is the stuff I’m taking for “fat” actually something a lot tougher & chewier? (Which would account for having to “saw” through it with your knife....)

Sorry to pepper you with questions, but I don’t know beans about pork..... ;)

All this math makes my head hurt, I just grab some cedars and sharp broadheads and go for it.

The thick, white stuff you see is the hard gristle that forms the “shield” on older boar hogs. It’s tough for even a sharp knife to cut through. The center streak you mentioned is the entry cut of the broad head. The arrow went through both sides and out, leaving a tremendous blood trail all over the cactus on both sides, as he ran for 5 seconds before crashing. Usually pigs leave a lighter blood trail than thin skinned game.

rallison- ashby tested lots of broadheads. sb and db. he got slightly better results with sb broadheads. his recommendations are the optimum config of everyaspect of his testing, but some of those recommendations only offer small or even negligible improvements.imo. some bhs were horrible. some were excellent (both sb and db). the biggest single factor was total arrow mass. not foc not skinny shafts not little fletchings not single bevels. the tests show the results. seems alot of folks are making assumptions based only on his recommendations not the tests themselves.

okaw is the poster the op was looking for. (and now me too) thanks for posting that okaw very impressive’

One of Dr. Ashby's conclusions was that "lack of penetration" is what caused most failures to occur.

Because bowhunting (especially with trad gear) is a very imprecise thing where all kinds of unforeseen animal movement or less than perfect shots happen the goal was to find what would work in those instances to result in a recovered animal.

So if an animal spins and your arrow enters the ham but goes on to hit the liver and exit the thorax there is a much higher probability of recovery than if it stops in the paunch.. missing the lungs but breaking both shoulders, same thing, two holes no matter the path are desirable. On perfect shots 7 or 8 gpp from a 43# bow work.

Some of us are getting older and shooting less bow poundage so it's interesting to know things like this. What CW was wanting to experiment with and hear from others, was just what kind of difference there might be in trajectories between 460 gr. arrows and 650 gr. arrows.

At 10, 15, or 20 yard trad hunting shots I think a day or two of practice would have you all lined out and now, I too, would like to hear from folks who are willing to give it a try.

Okaw, that is pretty telling results.

My #45@29” Vintage Super Grizzly just became a more capable weapon. Amazing penetration.. with a thick arrow too.

Playing with heavy arrows is really fun.

I made up some 9/32" solid fiberglass arrows that are made from pulruded fiberglass rod. They spine .600 and weigh 770grs. with a 125gr. broadhead.

They are as close to indestructible as an arrow can get. ANd they shoot well also. Due to the spine, you do have t play with centershot on heavier bows, but they tune just peachy.

I also made up some arrows on the same rod in 5/16 diameter. They weigh 900grs. with a 125gr. head. I can't recall the spine on those I'll have to look through my notes.

I used to shoot arrows made from bike safety flags... out of BOWS made from bike safety flags!! LOL. At that age, we shot what we had :D

Never shot a pig with one, but there was that one snake that I pinned it’s head to the bottom of the irrigation ditch as it swam by...

Stupid, reflexive shot that I never would’ve taken if I’d thought it’d had a chance of connecting...

Didn’t realize those are spined so light, though...

I don't think many of these folks have tried arrows that heavy out of bows that light. If you try it, you may like it. I messed around with my 34# recurve shooting 650-700 gr arrows the other day. I could be pretty darn accurate at 20 yds, plus it was silent.

I don't understand why people have to come on a thread like this just to defend their choices as "working just fine." I'm sure the do work fine, but that wasn't the question. Also, Ashby's research wasn't about working fine, it was about finding the best possible arrow setup. The difference may be slight, but I want all the factors I can control to be in my favor when hunting. I lost a deer to underpenetration out of a 65# bow when I hit shoulder. Sure wish I had been shooting an Ashby arrow -- though my setup at the time had "worked just fine" until that point.

Pete

Wow what did we do before all of these studies came out. I never weighed an arrow the first 10 years after I switched over to longbows. After reading more about efficiency and peoples articles about what works well for them, I paid more attention and always shoot 10 grains per pound to keep things rounded and easy to calculate but before I did I killed literally dozens of deer with arrows chosen strictly for their spine weights. The articles are entertaining and enlightening though.

I think we get misinterpreted a lot on both sides...will a heavy arrow out of a light bow work ? well yea, it will also probably be a little quieter.

Now hogs and thick skinned game are one thing, deer are another. You can't hardly lump all game animals together. Deer are pretty easy to kill and you don't need a telephone pole for an arrow.

GF I had to smile at your post....lol Guy makes a "good shot" and all he talks about is the broadhead like it preformed a miracle or something. Amazing how it works the other way also, Guy makes a "bad shot" and its the broadhead or arrows fault...lol... yea.

pete. i had a similar experience on a shoulder hit. i started paying attention after that!

This subject really interests me as I hunt with light bows. I'd really like to see someone do some good penetration tests comparing say 10 gpp arrows versus 13, 15, 17 gpp out of 35-40# bows. I know there is a point of diminishing returns, but I often wonder where that is with the lighter bows.

I do know the benefits of a heavier arrow for me have been a closer point on and quieter bow. As others have said the heavier arrows seem a bit more forgiving to form arrows and just seem to chunk in to the center of the target (could just be me...).

Jinkster did a very neat video some time back with a 30 some # bow and jugs of sand---and I believe a 3 blade broadhead.

Rick Barbee's penetration test are very good, but focus on much higher poundage bows than I can manage.

As I stated earlier, I usually shoot the same 10-11 gpp arrow for 3d as I do hunting to get the same cast. But I'd happily change my set up to hunting to something heavy if I knew it would perform better---I only take hunting shots out to 20 yards so the weight would not have a negative impact (pun intended) on my accuracy at that range.

I don't believe I'll ever shoot a trad bow that will allow me to penetrate the paddle bone, so I've been hunting a bit lower in the trees and from the ground lately. But as others have said better penetration on odd angles, etc. is never a bad thing.

Good thread and always good to see what others are trying.

I’m with George that a 650 grain arrow is not needed on a 45 # bow for white tails. A well tuned arrow is much more important to get pass throughs.

Hitting a deer in the sweet spot is what's important to get pass throughs with a well tuned arrow.

Hitting a deer in the not-so-sweet spot is what makes the case for a 650 gr. arrow from a 45# bow.

The rifleman, this data is showing a 40# bow with bone breaching and beyond penetration on buffalo bones comparable to 70 and 80# bows. You do have to make an effort on building the arrow.

CW above on here got to 650 pretty easy for his 43# Widow, another friend of mine got a pass through this fall on his buck with 535 gr. from his 38# bow.

https://www.grizzlystik.com/PR/Ashby_2008_Part2.pdf

"The rifleman, this data is showing a 40# bow with bone breaching and beyond penetration on buffalo bones comparable to 70 and 80# bows. You do have to make an effort on building the arrow"

Ive tuned pretty heavy arrows, so i understand the effort that goes into tuning. Just not sure about a 40# bow having penetration comparable to a 70 or 80# bow...

John....you aren't going to get the penetration from a 40# bow that you can get from a 70# bow.

What you can get provided you are shooting a bow of reasonable efficiency is an increase of probably 20 - 25% in penetration ability.

Now, that is if the arrow is well tuned and flying as straight as possible. (you know that already). However, that can make a considerable difference.

I am going to read up on that study before I pass judgment, but getting #70 or #80 performance out of #40 requires a violation of the No Free Lunch Law of Physics…

And of course no matter what you do, you’re not going to get a #40 to perform along side an #80 unless the #40 has been fully optimized and #80 has one hand tied behind its back and 1 foot stuck in a bucket.

One thought for rifleman, though…

Rick may do his testing with much heavier bows than you might care to draw, but it still comes down to GPP. What we’re trying to do is wring the maximum in efficiency out of our bows, and that is always going to be proportional. I have a really hard time imagining that a lightweight bow would perform well at 16 GPP but another bow with a higher draw weight would somehow perform poorly at that same 16 GPP. It just doesn’t stand to reason…

"Rick may do his testing with much heavier bows than you might care to draw, but it still comes down to GPP. What we’re trying to do is wring the maximum in efficiency out of our bows, and that is always going to be proportional. I have a really hard time imagining that a lightweight bow would perform well at 16 GPP but another bow with a higher draw weight would somehow perform poorly at that same 16 GPP. It just doesn’t stand to reason…"

That was kind of my point-- if i recall correctly Rick was getting best penetration w 9gpp. Very heavy arrows, not so much. I would think gpp would be somewhat of a constant, but not sure...

I can't get a decent click-on link in the reply window but to look at the charts I'm talking about simply search...

Ashby 2008 Update, part 2

Commonly used arrows

Second to last paragraph on the above page. Enclosed in a box.

"These results provide one of the clearest examples of the degree of penetration advantage that can be gained by optimizing the design features which enhance your hunting arrow's penetration potential. It's good news for those who are forced to hunt with a lighter draw-weight bow; especially when pursuing heavier game. It means they have arrow setup options which offer a penetration potential exceeding that of a bowhunter using a much heavier draw-weight bow, when the heavier bow shooter employs a commonly used, less efficient arrow setup. "

I listened to the Kifaru / Ashby podcast for a second time.

To clarify the comment about 40 vs 70 to 80 lb bows.

What the Ashby study showed is that the weight of the arrow was more important for breaking through bone then the draw weight or speed of the bow.

Agree on the draw weight, that's 'input'. Speed is 'output'. Momentum of the arrow is weight times speed. Optimum momentum can be determined buy shooting various weights of arrows from a given bow and graphing the resulting momentum.

At some number of grains of arrow you'll get the most momentum out of that bow, but just choosing some arbitrary figure is not how you determine that. (Neither is asking for 'opinions' on the internet ;-) )

X2 Glynn, CW, and Dana. Whether someone believes it or not, Ashby has already demonstrated what matters. And it ain’t draw weight or GPP.

Pete, the idea is to figure out what gets the best from a given bow. The Ashby results are what worked well from *his* equipment, which may not be optimum from a different bow. Not saying that heavier isn't better but there's a point of 'diminishing returns'. That is best determined by testing a specific bow.

I typed up several paragraphs of stuff here to show what testing I have done over the years, proof read it, then thought to myself - why? So, I deleted it.

Literally for years, I have offered folks the opportunity to test their penetration opinions, and theories, and do it into target mediums which will show them a consistent, and reliable outcome.

If I used my fingers to count the number of folks who actually tried it I'd have fingers left over.

The only thing I can say with "zero" reservation is:

"I know what works best for me, and you will never know what works best for you, until you've done the testing for yourself, and when you do you might be surprised by the outcome."

Rick

I agree Rick, you have to do your own test to see what works best for you and the bow you are shooting. I've been shooting bows for about 50 yrs and I've always messed with lots of arrows. Lots of guys are always searching for that perfect bow, I have several perfect bows, but I have always searched for that perfect arrow.

Wayne,

with the lack of interest & participation I stopped doing video of my testing on the foam blocks, BUT yes I've done some pretty wide change up on arrow configurations from 6gpp up to 20gpp, and various different FOC's.

To "increase penetration resistance", I also started using blunts instead of broadheads for a lot of the testing. What that did was allow me to see the delivered energy of the arrows (penetration wise) without any aid from a cutting factor. Once that was done I knew beyond any shadow of a doubt which weight & foc of arrow was delivering the most powerful punch.

After the arrow with the most powerful punch was determined, then it was just a matter of seeing which of the broadheads I had on hand made the best cuts to aid in the penetration of "that" arrow. The styles of broadheads did not show a tremendous difference from one to another, except for the single bevels, which have been a bit better across the board, followed up "closely" by 3blade.

In every instance, of every test I have done, and on every target medium I have shot, being somewhere between 9 & 10 gpp has given me the best penetration results.

FOC made very little to "zero" difference as long as it was kept at, or above 10%, and the arrows were flying properly. There was some lack of penetration when going below 10%. The one & only thing I found more FOC to lend some benefit to was it helps crappy flying arrows penetrate better, BUT not better than a well tuned/flying arrow.

Rick

I should add:

"I'll not hesitate" shooting just about anything in North America with a 45# bow at my draw length, as long as "I" am building the arrows, and have done "my" testing to see which work best for me.

"I'll not be" trying to shoot a cape buffalo with a 45# bow with "any arrow" under any circumstances other than a no other option survival situation. 8^)

Rick

Hey Rick - I’ve read up on some of your testing and applaud you for it. However, why do you think your results differ from Ashby’s results, which were repeatable and done in real flesh and bone? The only difference I can tell is that yours were done in manmade materials, which should be more consistent from shot to shot, but Ashby overcame that with repetition. I also just can’t figure how GPP made a difference in your tests either - since a target certainly shouldn’t “know” the difference between two 600-gr arrows at 160 fps, regardless of the draw weight of the bows that launched them. Any thoughts?

Pete

["Hey Rick - I’ve read up on some of your testing and applaud you for it."]

Thanks. I do this stuff for me, and my piece of mind. I want to know I have accomplished the best I, and my equipment are capable of, so I try it all to "satisfy myself", and occasionally share what I have found what happens to be working best "for me".

`````

Q1: ["However, why do you think your results differ from Ashby’s results, which were repeatable and done in real flesh and bone? The only difference I can tell is that yours were done in manmade materials, which should be more consistent from shot to shot, but Ashby overcame that with repetition."]

A1: Using a material, that "you know" is the same across every cubic inch of it (or reasonably close to the same) as your test material is always going to provide more reliable data.

Real flesh & bone will vary "almost always" from one animal to another, (even of the same species). In other words, and for example: Two 100# masses of flesh, and/or bone (from the same species of animal) will almost always have "different densities", therefore provide "different resistances" to something being thrust into them. So, unless bone & flesh density levels of each animal is scanned, sorted & used in like kind, and that data provided along with all other, there's no way of knowing how much "actual resistance" the arrows were up against from one shot to the next.

`````

Q2: ["I also just can’t figure how GPP made a difference in your tests either - since a target certainly shouldn’t “know” the difference between two 600-gr arrows at 160 fps, regardless of the draw weight of the bows that launched them. Any thoughts?"]

A2: GPP (G)rain weight of the arrow (P)er (P)ound of the draw weight of the bow - "will always" have an effect on how fast (or slow) that particular bow will launch the arrow. The faster the arrow is going, the more energy "the weight" of that arrow will deliver.

Draw weight aside, and considering only (weight:speed) of the arrow: You are absolutely correct. A 600 grain arrow traveling 160 fps will deliver the same energy regardless of what bow it is shot from, or what target medium it is shot into. BUT, there's no way where two bows (of equal efficiency), one being 45#, and the other 80#, where the 45#er will have that 600 grain arrow to out penetrate the 80#er. Not going to happen. It's not even going to be close.

I have found, that the (weight:speed) ratio works out best when the arrows are kept in that 9 to 10 GPP window at whatever draw weight the bow happens to be. From that point on, ("the only realistic way") to achieve more "arrow penetration energy" is to "go up in draw weight", and it gets even better if you maintain that 9 to 10 GPP arrow weight window as you go up with the draw weight.

Rick

2008 Study Update, Part 2 By Dr. Ed Ashby Part 1 of the current Update series presented the results of the 40# bow's Heavy Bone Threshold/FOC testing. In this Update we begin a comparison of the performance of those arrows to the results shown by 'commonly used arrows' from heavier draw weight bows.

Graph 5 Comparison: 40#@27" Recurve Above-Threshold EFOC Arrows vs. Normal/High FOC Arrows from 70#@27" and 82#@27" Longbows 9.45 9.61 10.75 9.25 9.83 12.5 Average arrow penetration 82# Bow, 190 gr. Grizzly broadhead 82# Bow, all single blade broadheads 70# Bow, all single blade broadheads 70# Bow, 190 Grizzly broadhead 40# Recurve, 723 Gr., 25.7% FOC 40# Recurve, 691 Gr., 26.2% FOC 82# Longbow, 190 Grain Grizzly Broadhead Average Mass: 792 Grains 82# Longbow, All Single Blade Broadheads Average Mass: 736 Grains 70# Longbow, All Single Blade Broadheads Average Mass: 963 Grains 70# Longbow, 190 Grain Grizzly Broadhead Average Mass: 725 Grains 40# Recurve, 25.7% FOC Mass: 723 Grains 40# Recurve, 26.2% FOC Mass: 691 Grains Graph 5 gives an a comparison between the two penetrationenhanced, above-threshold EFOC arrows from the 40# recurve and all comparable shots with Normal and High FOC arrows from the 70# and 82# longbows. Arrows from the heavier bows are shown in two groupings. The first grouping shows 'all single blades' while the second has only those arrows having the same broadhead used in the 40# bow's testing; the 190 grain Grizzly. To make the comparison with the 'normal arrows' from the heavier bows more applicable we're considering only the heavier bow's arrows at or below a total mass of 800 grains, and all shots where no arrow structural-failure was encountered. Only broadside, back of the shoulder thorax hits from the same shooting distance are included. © 2009, Dr. Ed Ashby All Rights Reserved While comparing, remember that some arrows in the heavy-bow groups do not possess as many penetration enhancing factors as those from the 40# bow. Some have a poor ferrule- diameter/shaftdiameter ratio, several have either 'Hill type' serrated, microserrated or file sharpened edges, and some have barrel-tapered shafts. Among 'all single blades' there is great variation in mechanical advantage, blade profiles, cutting angle, edge angle and tip profile. However, collectively taken they represent a typical aggregate of 'commonly used arrows' and single blade broadheads.

There is an up-side to making comparisons in which these many differences are present. It gives the light-draw shooter who uses a penetration-enhanced arrow an indication of how his arrow's penetration-potential stacks up against a heavier drawweight bow, when the heavy-bow shooter pays little or no attention to enhancing his arrow's penetration potential (other than having well tuned arrow flight). It also shows the fallacy of using only a bow's draw-weight as the guide to the "likely outcome" tissue penetration you can expect. The two above-threshold EFOC arrows from the 40# recurve compare very favorably with the average penetration shown by the 'all single blades' sets of 'commonly used' arrows from both heavier bows, and isn't far behind that shown for the 'same broadhead' sets. On heavy bone impacts they show, respectively, 2.2% and 3.9% greater average penetration than shown by the 70# bow's 'all single blades' group. They show 96.1% and 97.8% as much penetration as the 82# bow's 'all single blades' group. Compared to the 70# bow's 'same broadhead' group the 40# bow's penetration-enhanced, above-threshold EFOC arrows show 87.9% and 89.4% as much penetration, respectively. Even when compared to the 82# bow's 'same broadhead' group they show better performance than most would expect. Shot from a bow with less than half the draw weight they gave a 100% bone-breaching rate while averaging 75.6% and 76.9% as much penetration on heavy-bone hits. The heavier bow's comparison sets in Graph 5 are limited to single-blade broadheads; ether 'all single blades' or the same broadhead as used with the 40# recurve. What happens if we include all fixed-blade broadheads (excluding the mechanicals) in the 'common arrow' group for the heavier bows? This gives a truer cross section of 'commonly used arrows' for the heavier bows. (Mechanicals were excluded because their inclusion drastically lowered the average penetration.) © 2009, Dr. Ed Ashby All Rights Reserved Graph 6 Comparison: 40#@27" Recurve Above-Threshold EFOC Arrows vs. 'All Broadheads', Normal/High FOC Arrows from 70#@27" and 82#@27" Longbows 9.45 9.61 8.45 8.87 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 Average Penetration (in.) 82# Bow, all broadheads 70# Bow, all broadheads 40# Recurve, 723 Gr., 25.7% FOC 40# Recurve, 691 Gr., 26.2% FOC 82# Longbow, All Broadheads Average Mass: 788 Grains 70# Longbow, All Broadheads Average Mass: 755 Grains 40# Recurve, 25.7% FOC Mass: 723 Grains 40# Recurve, 26.2% FOC Mass: 691 Grains When all fixed-blade broadheads are included in the 'commonly used' Normal and High FOC arrows for the heavier bows there is a noticeable decrease in the average penetration. Compared to the 'all single blades' groups shown in the previous graph (Graph 5) the average penetration decrease for the 70# and 82# bow is 8.6% and 9.8%, respectively. That's fairly dramatic when one considers that only 10.5% of the 'all broadheads' shots are with multiblade broadheads. This reflects the marked difficulty multiblade broadheads have on heavy-bone impacts. When compared against the heavier bow's 'all broadheads' group the 40# bow's two penetration-enhanced, above-threshold EFOC arrows show a distinct penetration advantage. Against the 70# bow they show an average penetration increase of 13.7% and 11.8%, respectively. Against the 82# bow they show increases of 8.4% and 6.5%. Also remember that the 40# bow's penetrationenhanced, above-threshold EFOC arrows showed a 100% penetration rate on the hefty buffalo ribs. That's something that can't be said for either of the heavier bow's commonly used 'all broadheads group', where 47.1% of the multiblade broadheads and 10.9% of the single-blades failed to penetrate the entrance- side rib. In Part 1's 40# recurve testing we saw that the 50% of below-threshold Ultra-EFOC arrows that breached the entrance rib showed a large post-breaching penetration increase over the above-threshold EFOC arrows. How does the performance of these © 2009, Dr. Ed Ashby All Rights Reserved six Ultra-EFOC arrows compare with the above arrow sets from the heavier bows? Graph 7 Comparison: Average Penetration 40#@27" Recurve Bone-breaching Ultra-EFOC Arrows vs. 'Commonly Used" Normal/High FOC 'Single-Blade' Arrows from 70# and 82# Longbows All shots broadside, from 20 yards; Asian buffalo 14.0 10.75 9.25 9.83 12.5 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 1 Average Penetration (In.) 82# Bow, 190 gr. Grizzly broadhead 82# Bow, all single blade broadheads 70# Bow, all single blade broadheads 70# Bow, 190 Grizzly broadhead 40# Recurve, 620 Gr., 31.9% FOC 82# Bow's Normal/High FOC, 190 Gr. Grizzly, Average. Mass: 792 Grains 82# Bow's Normal/High FOC, All Single-Blade Broadheads Average. Mass: 736 Grains 70# Bow's Normal/High FOC, All Single-Blade Broadheads Average. Mass: 763 Grains 70# Bow'a Normal/High FOC, 190 Gr. Grizzly Average. Mass: 725 Grains 40# Bow's Ultra-EFOC Average Penetration for the six bone-breaching shots The average penetration for the 40# bow's six bonebreaching Ultra-EFOC arrows exceeds that of each heavier bow's 'all single blades' and 'same broadhead' groups. The percent of increase in penetration they show over the other groups, from top to bottom, is: 12%; 42.4%, 51.4% and 30.2%. Now let's factor in the multiblade broadheads and look at the two heavier bow's 'all broadheads' groupings. Graph 8 Comparison: Average Penetration 40#@27" Recurve's Bone-breaching Ultra-EFOC Arrows vs. 'Commonly Used' Normal/High FOC 'All Broadheads' Arrows from 70# and 82# Longbows All Shots broadside, from 20 yards; Asian Buffalo 14.0 8.45 8.87 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 1 Average Penetration (In.) 82# Bow, all broadheads 70# Bow, all broadheads 40# Recurve, 620 Grains, 31.9% FOC 40# Bow's Ultra-EFOC 70# Bows Normal/High FOC 'All Broadheads' Average Mass: 755 Grains 82# Bow's Normal/High FOC 'All Broadheads' Average Mass: 788 Grains Average penetration for the six bonebreaching shots. © 2009, Dr. Ed Ashby All Rights Reserved Average penetration for the six bone-breaching Ultra-EFOC arrows from the 40# bow is 65.7% greater than that shown by the 70# bow's 'all broadheads' group. They show 57.8% greater average penetration when compare to the 82# bow's 'all broadhead' group. While the performance of the six bone-breaching hits with the below-threshold Ultra-EFOC arrows from the 40# recurve are little short of astonishing there still remains that threshold barrier. If we consider the overall penetration average for all its shots; the six bone-breaching hits and the six shots stopped by the rib; how do the below-threshold, penetration-enhanced Ultra-EFOC arrows stack up against the Normal/High FOC arrows from the heavier bows? Let's look at that comparison. Graph 9 Comparison: Average Penetration All shots, 40# Recurve's Ultra-EFOC Arrows vs. 'Commonly Used' Normal/High FOC Arrows from 70# and 82# Longbows 9.5 8.45 9.25 8.87 9.83 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 1 Average Penetration (In.) 82# Bow, all single blade broadheads 82# Bow, all broadheads 70# Bow, same broadhead 70# Bow, all broadheads 40# Recurve, 620 Grains, 31.9% FOC 40# Recurve's Penetration Maximized Ultra-EFOC Arrows 70# Bow's 'All Broadheads' Normal/High FOC Arrows Average Mass: 755 Grains 70# Bow's 'All Single Blade' Normal/High FOC Arrows Average Mass: 763 Grains 82# Bow's 'All Broadheads' Normal/High FOC Arrows Average Mass: 788 Grains 82# Bow's 'All Single Blade' Normal/High FOC Arrows Average mass: 736 Grains Many will consider the results shown in Graph 9 a fairer and more direct comparison of the performance of the belowthreshold, penetration-enhanced Ultra-EFOC arrows from the 40# recurve. In some ways that is true; it does show the overall "likely outcome" penetration for a heavy bone hit. On the other hand, in some aspects the "likely outcome" is skewed in favor of the arrows from the heavier bows. Why is there a skewing of results in favor of the arrows from the heavier bows? The Heavy Bone Threshold is highly dependent on arrow mass. The vast majority of arrows in each heavy-bow grouping have a mass-weight exceeding the heavy bone threshold. In fact, 82.7% of all shots shown for the 70# and 82# bows are with arrows having a mass-weight above 650 grains, © 2009, Dr. Ed Ashby All Rights Reserved whereas 100% of the 40# bow's Ultra-EFOC arrows had a massweight below threshold value. This gives arrows from the heavier bow a decided 'opportunity advantage' to show post-breaching penetration. Despite the handicap imposed by the Heavy Bone Threshold, average penetration for all 12 shots; the six shots breaching the bone and the six not penetrating the bone; the 40# bow's below-threshold, penetration-enhanced Ultra-EFOC arrows exceeds that of each heavier bow's arrow grouping shown, except for the 82# bow's 'all single blade' group. Even this group only exceeds the Ultra-EFOC arrow's overall average penetration by 3.5%. That's pretty dramatic average penetration when one considers that 50% of the below-threshold Ultra-EFOC arrows were stopped by the entrance side rib! For now, one can only conjecture what the outcomes would have shown had the 40# bow's penetrationenhanced, Ultra-EFOC arrow had a mass-weight above- threshold.

These results provide one of the clearest examples of the degree of penetration advantage that can be gained by optimizing the design features which enhance your hunting arrow's penetration potential. It's good news for those who are forced to hunt with a lighter draw-weight bow; especially when pursuing heavier game. It means they have arrow setup options which offer a penetration potential exceeding that of a bowhunter using a much heavier draw-weight bow, when the heavier bow shooter employs a commonly used, less efficient arrow setup. In Part 3 of this Update series we'll look at what both these and the other Heavy Bone Threshold test tell us about the effect impact force has on the threshold value and more about how the degree of arrow FOC affects post-breaching arrow penetration.

Crap! can't get the graphs to show.

Thousands of animals, hundreds of bow and arrow and components combinations. Broken down into information that you can use to maximize your personal bowhunting needs.

The 12 arrow penetrating enhancing factors in order of importance alone is worth the time to read. You can decide based on what game you hunt how many relate to you.

If all you hunt is squirrels and 100 lb. deer you might not bother but if like the OP, you want to know how to have the utmost confidence in your 43# longbow in less than perfect situations it wouldn't hurt to spend a few hours going through the segments that pertain to your circumstances.

Take what you like and leave the rest. or not :)

That’s the good stuff Glynn. Inject it straight into my bowhunter/scientist veins! Here’s the link.

Interestingly, that part of the Ashby study also shows a 40 lb bow with heavy EFOC arrows and Grizzly broadheads matching the penetration of 70-82# bows with heavy arrows and normal FOC and other 2-blade heads!

Rick, I completely understand your premise and think it’s theoretically valid; however, Ashby overcame the inconsistencies of flesh and bone by repeating, over and over, his testing, in different animals, and averaging the results. Sounds like you found a specific velocity that seemed to work best for penetration in your medium that was probably in the 170 range (somewhere around what an average bow shoots 9-10 GPP). Interesting.

This site soooo needs updated for linking and graphics purposes

I’ve shot lots of arrows into foam, cardboard, and straw. The difference in penetration, I believe, was mainly due to the point and shaft diameter, shaft material, and arrow flight. Material like those don’t show real world, hunting, flesh and blood performance.

You will never find a man made medium that duplicates animal hide, hair, fat, blood, muscle, gristle, and bone.

With foam blocks you mostly test the fiction resistance of the point and shaft.

https://www.grizzlystik.com/PR/Ashby_2008_Part2.pdf

I don’t see the link I added - here it is.

[[[ "You will never find a man made medium that duplicates animal hide, hair, fat, blood, muscle, gristle, and bone." ]]]

That's a fact.

Resistance is resistance regardless of the material, and (cutting/slicing ability aside), it takes energy to overcome that resistance.

Those man made materials (many of them) tax the penetrating ability of an arrow much more than an animal will.

So, when using those "very energy taxing" man made materials, drawing the conclusion, that an arrow penetrating them "best", will also penetrate an animal "best" is pretty easy. At least for me it is.

To your point about the friction thing:

My good friend GLF (Gary Fulk) mentioned testing with lubrication. So, on both the foam blocks, and on the plastic barrels, several times I lubricated the arrows entirely (end to end, including the broadhead/point) with Slick50 to see how much difference it would make. It made zero difference on the plastic barrels, and on the foam blocks the difference it made (when it did) was never more than 1".

I can feel a challenge brewing. 8^)

Rick

I just read the "terms & conditions" of the site.

Nowhere in them does it say you can't make any friendly wagers.

I'm working on something. 8^)

Rick

Until you can come up with a foam that lubrictes the arrow with blood and fat; the penetration tests are invalid. A larger shaft arrow will not penetrate as well as a skinny arrow in foam. Doesn't matter what the KE is. An arrow tHat has a larger head than the shaft will penetrate better than one that has a smaller diameter point than the shaft, because the larger point will open a channel for the shaft, and allow better penetration.

Lubricate the arrow with fat and blood, and the surface tension is almost gone. Only the point itself matters the most. The shaft will slide through skin and meat without the kind of resistance it meets in foam.

Chuck, yes I agree - skinnier diameter shafts have an advantage, simply because they are not having to displace as much material as they move along, but all broadheads make a hole bigger than the shaft no matter how fat it is.

Use a blunt a little larger than the diameter as the shaft, and when you do - it is only brute force getting you any penetration. I guarantee you, the arrow that penetrates best with only brute force will also be the one to penetrate best with a broadhead on it. Lubricated, or not.

Rick

And, with that I'm out of this one.

Everyone knows how/where I stand on the topic, and if not a simple search will find you quite a bit of stuff I have shared about it over the years.

If I come up with something for a penetration competition (with prizes) I'll post it up in a new topic.

Rick

If anyone is interested in reading Dr. Ashby's studies they can be found on Tuffhead Broadhead's website. Lots of good info!

I at one time tried 650 grain broad heads with a 56# bow. I ended up being disappointed and went back to around 10 gpp with double bevel. I wasn’t getting the passthroughs I thought I would get. It’s was if the single bevel disrupted the momentum after impact with a live deer. That was just me and I really can’t explain it.

Mostly this is an answer searching for the problem.

Just looking through this thread and I count 8 people that are using a heavy arrow , light bow combination and are happy with it.

One person tried it and did not like it because of the trajectory.

A lot of good discussion and arguments on both sides of the fence. Thanks to everyone for posting.

My new big game bow. 1970s Super Grizzly 45.5@29” I bought this about 13 years ago with the price tag still on the limb. It was work to get it off after 30+ years.

That is about 15gpp which is about what I shoot with some of my 60 pound bows and 900 grain arrows. When I am asked why I shoot such heavy arrows my answer is always a simple one, "because I can". The pleasure of living in the free world is that we are free to do things as we deem appropriate. I have a longish draw and have always shot heavy arrows.

DDave

That is a great set up ! 14.4 gpp.

I am a fan of heavy arrows. Although I shoot a slightly heavier bow, 47-48 lbs. , my set up is 29" Gold Tip Classic 400s and 250 grain VPA 3 blade broadhead. Finished out at 710 grain- 14.75 gpp.

Worked out great this year!! Shot was 18-20 yards and not perfect, hit on front of shoulder, broke off 1" wide x 3 " of bone. angled thru the heart and cut off rib on opposite side. Tip of broadhead just broke the hide. The buck was down in 35 yards. Field dressed 145 lbs.

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