arrow weight v. speed for penetration

[elkaddict]

I hunt with some guys who have been bowhunting longer than I've been breathing. As a result, I'm hesitant to blow off there advice since I've only gotten back into bowhunting after a 25 year break. I'm shooting 27" goldtips with 100g broad heads at 278fps. These experienced hunters tell me I would be much better off with heavier arrows, or at least 125g heads. At what point does some extra weight make up for lossed arrow speed when it comes to penetration? Part of my excitement with new bow technology is how fast they shoot--25 years ago, I couldn't have imagined having the first pin on my sight set at 25 yds. This bow shoots flat enough that I think it makes sense. Is it worth giving up some of that speed? What kind of increased penetration can I really expect with 25g of additional weight? Does the analysis change if the game is elk rather than big mule deer? My sense is that some guys really do take the speed thing to extremes--my hunch is 278 fps with 380g arrow is not too far on the extreme. Any thoughts or suggestions? This last year I shot 100g slick tricks with good results. I'm contemplating a switch to the 85g slict trick which 5 shot reports penetrate like crazy. I'd appreciate some advice.

[akaSharkey]

Normally you will get more KE from a heaver setup. I tend to go that route. Here is a link to the KE caculator on goldtips site. http://www.goldtip.com/calculators/kinetic.asp

[TFOX]

HERE WE GO AGAIN.


If you are comparing apples to apples they are correct in the fact you will have more momentm and have better luck with a bone hit.But we aren't comparing apples to apples.You are comparing carbon to aluminum.In general carbon is tougher and will not flex as much on impact.On the otherhand,if you are using a thickwalled aluminum,you offset some of this so If you choose to take their advice,make sure you use atleast a wall thickness of .015 if you think there may be a problem with penetration.


From the looks of your setup,You won't have a problem with penetration.

[Bigpapascout]

I will not debate this one any more because whether you shoot heavy slow or light fast set up will still carry enough energy to pass thru a moose with proper shot placement.

My primary hunting rig shoots a 260 GN 9/32 dia arrowusing a 2" long with a 5/8" profile vane traveling 355 FPS 73 pounds energy off the string ,
at 60 yards is still carrying 59 foot pounds of KE and still traveling 319 feet per second and has only dropped 57 inches.

a bull elk can be killed with less than 50 pound bow resulting in a compleete pass thru producing 50 KE or less, what is more inportant above these specs isif you are comfortable using what you already have, shot placement.
and what the state you hunt in will allow you to hunt with.

[Arthur P]

I agree with your friends, elkaddict.

I disagree with TFOX, that this is an aluminum vs carbon debate. Might used to have been so, but now there are various heavyweight selections in carbon and carbon/glass composites. I've come to be pretty partial to Carbon Express Terminator Selects, a carbon composite arrow with almost exactly the same weight as an Easton XX75 2315, the same diameter as most ICS type carbons and, from my experience shooting them, better toughness than all-carbon arrows. All the benefits of carbon plus decent weight without absurd weighting systems. What's not to like?

BPS posted on another thread that he couldn't get Phantom broadheads to fly straight. Look at the numbers he posted and you should easily see why. I believe I also remember him saying the broadheads he shoots are less than 1" diameter. Is that correct, BPS? Frankly, I'd rather have a big broadhead on a slower arrow, poking a 1 1/4" - 1 1/2" hole thru the heart/lungs than an identical hit with a faster arrow, but a hole less than 1".

I'll also gladly forsake some speed to take the easier tuning, better reliability and better 'forgiveness' of heavier arrows, and have a bow that consumes much less of my time with retuning and maintenance to boot. Less time spent tuning and working on my bow leaves me more time to enjoy SHOOTING the darn thing.

Heck, even if a heavier arrow drops you down to 240 fps, your arrows are still screaming fast compared to whatever you were shooting 25 years ago!

[TFOX]

Hey Arthur,I just did a quick check for a 30" hard 2 cam bow at 70",s.The heaviest all carbon you could get with a 125 gr point was 488 grains.That would be considered light when compaired to a thick walled aluminum shaft for the same bow.There was only one anywhere neer that heavy,unless you count the composites.


Are you conceeding that carbon penetrates better than aluminum.

Just kidding Arthur.


I am still in favor of good spine,good balance,carbon or carbon composite shafts ,properly tuned and well placed arrows over just weight at any cost.I am increasingly more in favor of the ACC's because of some of the issues that some seem to have with broadhead flight on carbons.

[Arthur P]

Are you conceeding that carbon penetrates better than aluminum.

Only when you stuff the weight of an aluminum into the shaft diameter of a carbon. Of course, when you puff that light carbon up to the size of a 2512 aluminum...

I've still not convinced that an arrow - of any material - flexes at all as it's passing through an animal's chest cavity; unless the animal moves at the beginning of penetration or unless the arrow hits heavy bone. IMO, this is the carbon manufacturers taking a grain of truth (ie: how carbons vs aluminum arrows act when they come to a dead stop in a target butt) and blowing it all out of proportion to create a myth. Then they started spreading it in order to boost sales.

Dr Ashby's studies - which are the only true penetration tests done on a scientific basis with actual game animals in the field - affirm the effects of shaft diameter, heavier total arrow weight and broadhead design and lend no credence to any hypothetical shaft flexure.

[elkaddict]

Maybe I didn't ask the question well. Is adding 25g of weight with the corresponding loss of 8-10fps really going to penetrate more? At some point, the loss of velocity has to affect penetration too. I can clearly see how shooting arrows that are a 100g heavier would have more momentum/penetrate better. But without going to this extreme, is there a significant advantage by jumping 25g in weight? I prefer 4 blade broadheads for the additional cutting area--I also understand that it takes more energy for them to penetrate than say a similar cutting width 2 blade. I'm jsut trying to figure out a good balance of penetration and speed with optimum cutting area.

[Arthur P]

Is adding 25g of weight with the corresponding loss of 8-10fps really going to penetrate more? At some point, the loss of velocity has to affect penetration too. I can clearly see how shooting arrows that are a 100g heavier would have more momentum/penetrate better. But without going to this extreme, is there a significant advantage by jumping 25g in weight?

Well, that makes it a simple answer. No.

Unless the extra 25 grains makes your arrows spine out better, fly cleaner and more accurately, and hit straighter....[:-]

[Bigpapascout]

BPS posted on another thread that he couldn't get Phantom broadheads to fly straight. Look at the numbers he posted and you should easily see why. I believe I also remember him saying the broadheads he shoots are less than 1" diameter. Is that correct, BPS?

P
I tested the phantoms on a 75-95 using 4" RH feathers the arrows speed was 272 FPS
my Broadheads are 1" cut diathat have already killed 3 this year
large cut diamiter heads wont do you worth a flipif you cant keep them from planeing out of the kill zone.

arthur if you like your set up fine
but I would apreciate it if you would quit making enuendos that mine is inferior to yours when it have prooven its self time after time.
Thanks in advance