More on the "heavy arrow" debate

[eagle24]

I've searched, researched, and read everything I can find pertaining to heavy arrows, hunting weight arrows, kinetic energy, momentum and anything else that seems to be related to finding the best hunting weight arrow for a particular bow.  It seems like all the information stops short of being proven and in the end is somewhat subjective.

A few things that I have been pondering:

Draw weight - I've seen posts and read threads that start out "What is the minimum weight bow that should be used.....".  These discussions (most of the time) tend to be relative to draw weight without consideration of the bows efficiency.  Why would minimums not be stated in terms of ???gr arrow at ???fps?

Kinetic Energy - Seen posts on minimum kinetic energy for hunting (whatever).  I've calculated Kinetic Energy on two different weight arrows from the same bow to be equal.  I know (or at least I think) that the heavier arrow with the same KE is best.  Does Kinetic Energy (alone) really mean anything?

Is there an optimum arrow weight for a particular bow? or is heavier always better, with no upper limit on arrow weight?  I realize that as flatness of trajectory decreases, "efffective range" will also decrease for everyone, although it will be different from one shooter to the next.

I'm to analytical, but would like to hear what others think.

[longbowman]

Eagle,   I guess anybody can analyzie themselves to death over just about anything but logic "should" prevail in anything.  I'm an engineer by trade and you can caluculate the crap out of a particular problem and in the end you use what actually works.  As for arrow weight vs efficiency vs speed stuff...It's the arrow that hits the deer not the bow limb design.  It's just common sense that if I put a razor sharp broadhead on a drinking straw and one on a ten pound spear and threw them both at the same speed, which do you want to hit you?

[NoCams]

Greg,
From what I have seen of your shooting and them there Adcock bows, it really does not matter. 400-500 grains are good round numbers for arrow weights for your bows. Pick one for goodness sake and let's go kill something with R.L. !!! What broadhead ya gonna hunt with ??? Me and Mason are going to shoot both 125 Phantoms and Wensel Woodsmans and see what works best. But then again, them Treesharks, what a wicked looking head !!!

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[NoCams]

Did I mention that we got drawed for Illinois too !!! As a matter of fact they had about 1400 left over non-resident tags left over !!! They go on sale Aug 6th 8AM CDT.

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[eagle24]

Frank, You're right.  Hopefully, I incorporate some logic into everything I do.  I guess what puzzles me is that many of the discussions lack a lot of (what I would consider) pertinent information.  For instance, if I asked you if a 70lb bow was heavy enough for moose.  Would it matter to you whether it was a hickory self bow or a Schafer Silvertip Recurve? or if I said is 40 ft lbs enough kinetic energy for whitetails?  and then told you I was using a 20gr arrow traveling 950fps.  I know that is ridiculous, but how can you talk kinetic energy #'s or draw weights without any other info?  

Dr. Ashby's reports make more sense than anything I have studied, but you have to read everything and understand what's going on.  I've read all his reports once, and several pieces more than once.

[RamiusEng]

I suspect there is a weight range, where regardless of the weight of the arrow they will have very similar KE's.  Then the momentum crowd chimes in..... I would suspect that momentum will be the final judge on how well the arrow penetrates.

So the question for anyone is do you need the flatter trajectory or the penetration to make a humane harvest?  I suspect that answer changes with shooting styles and skill levels.'

Just my $0.02

[eagle24]

Jimmy,
I was typing while you posted.  I'm gonna shoot 460gr from 41# & 500gr from 45# with 125gr Stinger on each.  Glad you're going to IL also!  Somebody outa get a good shot opportunity at a P&Y buck.  Sent you a PM.  Wanna ask you about a GPS.

[doctorbrady]

This is a quagmire of an argument.  Simply for the reason that it is difficult to prove from data taken from live animals.  Few are willing to autopsy and catergorize every animal that they take, assuming they take enough to give credible evidence.  That said, Dr. Ashby has come about as close as I believe anyone can.  
My take from what I have read and experience over the past 20 years of bowhunting is that bigger is almost always better when it comes to arrow weight.  That flies in the face of KE studies, but critters are not made of ballistic jelly and momentum plays an important role on penetration.  That said, you have to shoot a weight which is reasonable enough to allow you to hit your target.  An 800 grain arrow from a 40# bow (assuming you get find one spined correctly) just won't allow for much more than a 5 or 10 yard shot.  Also, if you are stalking antelope with your 50# recurve you may not want to go 15 grains/inch as your shots may be a little longer.  
Myself, I like 10-12 grains/inch from fairly high perfomance bows on big critters, but scale down to 9 grains/inch on smaller thin skinned critters when I expect my shots may be a little longer.
Just my 2 cents.

[Seeking Trad Deer]

no debate...heavier equals more humane via better penetration.  How heavy...well that could be debated...

[eagle24]

Brady, There you go introducing more logic into the quagmire.  I'm thinking the same as you.  Any shooter, with any degree of common sense, will stop on arrow weight due to the sacrifice of trajectory, long before he's too heavy from a penetration performance standpoint.  I shot some 715gr arrows from my 41# bow last night.  They really looked slow.  I had to ask myself would they really outperform the 460gr arrows?  I'm guessing they would, but they looked SLOOOOOOOW.

[Rick McGowan]

KE is pretty much useless as a precurser of penetration, at least as you start adding variables. Momentum is better, but still there are all those varibles. Penetration tests on live animals would be the best, except it is impossible to duplicate the same shot twice. I did a bunch of penetration tests and what I found was that whatever worked best in one test medium worked best in ALL mediums, however it is REALLY hard and tedious to do accurate and thorough penetration tests. Heavier is ALWAYS better for penetration, no limit, however as pointed out tradjectory is a limiting practical factor AND on most game animals, penetration isn't that much of a problem anyway if you are shooting a reasonable bow and well tuned arrows.

[pseman]

I believe that "minimum draw weight" and "minimum KE" will change depending on the shot and sharpness of broadhead. That being said, I don't believe in hunting with the "minimum". I also don't like shooting spears that arch like a 3pt shot. I prefer to shoot a set-up that is comfortably above the "minimum" but flies on a trajectory that I can shoot accurately.

For me this is an arrow between 400-550gr traveling 165-190fps(faster speed for lighter arrow). This is more than adequate in my opinion. More weight may penetrate better in some situations, but if my accuracy with that heavier arrow is bad, then I'll just get a deep penetrating bad shot.

[Shawn Leonard]

All I know is carbons at the same weight as woodies and alum. penetrate better all else being equal. I also know that 8-9gpp. out of hunting weight bows 40#s and up at the persons draw, is more than enough for any game I hunt up to and including whitetails. Shawn

[vermonster13]

If you're talking whitetails, what matters is arrows that shoot straight and tune well to your bow. Never even knew about weighing arrows for the first 30 deer I killed. Just shot what worked best with each bow. The rest is mostly talk to fill the off-season.

[NoCams]

vermonster nailed the lid shut with that one !!! Now off to another thread......

   

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[JC]

Doctor brady...you are spec'ing gr/in....that would seem to awfully light if you shoot heavier pound bows: 29" x 10gr/" = 290gr...from a 60# bow this could potentially be disasterous. Am I to assume you mean grains/lb of bow weight? I shoot shafts in the 9-15gr/" category but the finished arrow is far heavier than that gr/" spec.

Greg, I'm with Jimmy, the way you shoot, I think you may be overthinking it some...but that's some of the fun of this stuff    Most bowyers recommend 8gr/# of draw weight or better for the finished arrow weight as safe for the bow. Doc Ashby has proven, at least to my satisfaction, that heavier is always better for penetration. Like you and others have alluded too, there is a common sense limit that says their is a point where poor trajectory makes the heavier arrow more difficult to shoot accurately, thereby limiting range.

Personally, I think bow weight should be considered. Out of a 40# bow for whitetail, you may get away with 9gr/#...but I wouldn't recommend it. In that extreme, I would prefer to see the guy shooting 450+ grains, because he doesn't have the horsepower to spare so he needs to make it up with momentum. Out of a 55# bow, 9gr/# wouldn't seem out of perspective at all, some enjoying great success on whitetails down well below that mark...but they aren't shooting 40# bows either.

And yes, the draw length and bow design both play a large part that is often overlooked. Longer draw = longer power stroke = more energy so you can shoot less # than us short armed runts and still get equal performance. A highly efficient bow at 50 is gonna be a better performer than a 70# self bow in most cases.

I've seen you shoot and I've seen your arrows fly...I don't think there's any reason why your setups shouldn't work on deer. Increasing your arrow weight will definately add a bit more insurance to the shot, but only if you are not sacrificing confidence and accuracy for that insurance.

[Shawn Leonard]

JC, if ya draw 30"s though with that 40#s it makes adifference. I know Chad Jones has been shooitng some big whitetails with a 50# zipper and arrows that weigh around 375 grain or just over 7gpp. I blew thru a nice buck and a big yote last year with a 42# Widow and a 340 grain arrow. I used to think that way and always shot 62-65#s and arrows 575 and up, but now with my bad shoulder and lighter weight bows, I have learned a few things. Shawn

[JC]

I understand your experiences Shawn, but I still think those arrows are too light for me and where I hunt. I've seen my arrows go through both shoulder blades of a deer that jumped the string....I doubt I can get that kind of confidence with light arrows and light draw weights. Yep, they will work great if everything goes perfectly...but I'm not that lucky so I prepare for the worst case and am seldom disappointed.

[James Wrenn]

The more I think about all the numbers the more I realize they don't really mean a lot for what or how I hunt.Light arrows, heavy arrows they all work just fine if they have sharp broadheads on the front.If I was shooting blunts and trying to knock them down it would be differant. ;)If I ever plan a trip to Africa or down under I will check up on the numbers.For deer and hogs I feel it is a waste of time if you are shooting a legal bow weight and don't have t-rex arms.    jmo

[Landshark160]

Here's another angle.  Do you prepare for maximum penetration by shooting a narrow two blade head, or do you go with the widest four blade head you can find in case of a gut shot?