PERIOD
Joe
PM me for more info , we call also talk on the phone.
Kirk
Easton N-Fused Axis 300 (11.5gpi) tipped with a 125gr.
Come to Idaho and hang out with some of the speed freaks. :0)
Kirk
Kinetic Energy is more important than total arrow weight. Figure your KE (use the tools on this site) and you'll know where you stand.
What does how you shoot at 80 to 100 yards have to do with hunting with a bow. I can shoot about as well as anyone at that range buttttttttttttttttt. Thats really stretching it. If a person keeps their shots within their effective , comfort range then arrow weight is important.
IMO, you're a little light - you could do the trick with those arrows, but you could certainly stand to go a little heavier. I'd try something in the 10+gpi range and see if you can get it to tune and are comfortable with the results.
372 grs. will work if everything goes right (heck, 300 grs. will too), but why work up an arrow that is positioned for when everything goes right? Put some thought into what arrow will work when something goes wrong (i.e. animal movement, heavy bone, or just thick hide/muscle).
At the risk of repeating myself on this forum, I shot a big bull last year and got 16"-18" of penetration with a good flying COC BH-tipped 440 gr. arrow at around 275 fps. The arrow had to push through a mud-caked hide and the full thickness of the shoulder muscle, and did not even protrude through the far side of the heart. The elk dropped within sight, but 4" less penetration would have resulted in 1 lung and presuimably a long tracking job. Who knows what result 75 grs. less arrow weight would have yielded? Maybe 4" less penetration?
I am going to use that, and will send you a nickle each time I do.
When I stared shooting a bow , speed was everything , but I had not killed S#!T to speak of, but I was positive my 350 gr arrow would go through anything!!!
Now I shoot a 590gr arrow and have killed over 100 animals. The arrow weight keeps going up every year:)
The test I ran certainly would not be considered "scientific" nor would any tests on real animals where no two shots can be duplicated. Bone and tissue density variables, blade orientation to bone, rib flex and may other variables can not be duplicated to give a scientific test on real animals.
My test in foam was able to control these target variables, but other variables were NOT controlled.
I used three different brands of arrows, the Martin Cougar Graphlex XT 17-8, Carbon Express Maxima 250, and the Cabela’s SST 240 pultruded shaft. Total arrow weight varied from 346.7 grains for the Maxima with a 100 gr tip to 658.7 grains for the martin with a 150 gr tip.
None of the arrows used were exactly like those for which my bow was tuned. I changed only one variable with each arrow brand, that was the weight of the point. By doing so the dynamic spine of each arrow changed as tip weight changed, thus changing the "tune" requirements. Changes in arrow diameter also effected the tune.
Also, all of the arrow were shot at about 2 yards to ensure that I would not hit a previously hit spot on the target and also no hit my chronograph. Even a tuned arrow would not have stabilized from parallax at that range.
Since the bow was never perfectly tuned to any of the arrows, but all were close, yet the results from three shots were consistent for each arrow brand, I consider the results worth noting.
The penetration varied from 11.75" for the 100 gr tipped Martin to 13.97" for the 100 gr. tipped Cabela's skinny pultruded shaft. Even adding motor oil to the shafts did not meaningfully effect penetration.
Actually a slight reverse correlation for penetration was seen by adding weight to all but the Cabela's pultruded shaft. (more weight actually lessened penetration)
Only the Cabela's pultruded shaft showed and increase (10 % ) in penetration with a 150 gr increase in weight. The Martin lost 2% in penetration despite a 15.77 % increase in momentum and a 3.16 increase in KE. The Maxima lost 2.38% in penetration despite a 22.84 % increase in momentum and a 5.05 % increase in KE.
This is why I continue to say that KE is a better of indicator of penetration than momentum. But more and better tests need to be ran.
None of the tests were double blind. I've never seen a penetration test that was.
Different results may be seen by using weight tubes or by changing arrow spine. I highly recommend that each of you do your own penetration tests to see if the trade-offs in penetration, noise, trajectory, etc, are what you are willing to pay. Each set-up can be different.
If it ever cools down around here I would like to redo the test at a greater range and re-tune for each arrow brand and weight.
IMO that is like coming to the conclussion that you proved that by decreasing the weight of a frog you proved that it would jump a shorter distance rather than a longer distance, based on decreasing the weight by cutting off its back legs.
I guess my point is, what works in theory doesn't always prove out in the real world. I understand momentum, and have always been a advocate of mid weight arrows and bullets, but in this (my) case, the light weight projectile is proving to be the most efficient. One compromise I did make for penetration is moving to a smaller diameter broadhead. I'd rather have a 1" broadhead through and through than a 1.25" half way in.
And I already said that even a perfectly tuned bow would not have perfect flight at that range.
It certainly was not a test that will forever settle all disputes about weight and penetration. It did, however, certainly opened my eyes to how little effect that adding even 150 grains can have with my setup, under these conditions contrary to much of the BS that is parroted on this site. More tests are needed, but a trend SEEMS to be establishing for my setup.
Tests in harder media that simulates bone may give totally different results. Again, more tests are needed.
Anyone else care to make an uninformed comment based on pure speculation, or antidotal evidence.
I will be impressed if you added the 150 grs. in a way that did not change dynamic spine, but I can virtually guaranty you didn't.
"I guess it is safer to rest on opinions and nonrepeatable tests rather than consistent repeatable data."
That belies the body of evidence that exists as the result of work done by the likes of Woody (which incidentally contradicts your findings). What it comes down to is whether one places their emphasis on repeatability of testing or the relevnace of the test medium. When the results diverge, I will take the medium.
I'd have to look it up again and don't feel like it, but if I remember a .22-250 and a 45-70 were close to the exact same ME. One uses a 405 grain bullet the other 50 or 55 grain. One is a smokin' hot sub 4000 fps laser, the other plods along at 1200 or 1300 in a big ol rainbow some folks claim they can see.
One I wouldn't give a second thought to hunting anything in NA with including dangerous game. It can and has done all that very well in it's illustrious history.
The other I would question your sanity on anything bigger than a deer. OK, probably even the deer. It's hell on groundhogs and prairie dogs though.
Admittedly extreme examples. But the lesson is still relevant. Both examples had the same KE. KE measures KE. Not penetration, efficiency or suitability.
Oh, almost forgot. I'd really give a lot of weight to the experienced elk hunters up above here are saying. Between them they have a few truckloads of elk and other BIG game on the ground. A 40 footer from Bigdan alone.
I'm talking back in the 80's when I was shooting 2213's from an overdraw at 300+ fps. I suppose I could have figured it out on my own when seeing those arrows hit something hard and just disintegrate.
BTW, That was a tactful way to say all of the foam, steel drum etc tests are BS
but if it comes down to "should i goof with my set up 3 weeks before the season to mess with arrow weight and not shoot these 375 grain arrows that shoot GREAT for ME and i have TONS of confidence in???" NO BODY would say YES. period.
i dont get caught up in this hype much, because i have in the past....i have seen/heard/known of TONS and TONS of elk that have been shot with gt5575, most people shoot those right at around 400 grains.....perfect in my opinion. Just about every guy i shot with or hunted with for 4 years in oregon shot gt5575 at the BIGGER bodied rosey elk.....and every year DOZENS of pictures were being placed on the wall behind some very nice elk.
I love the stories about "a buddy shot one with an arrow that was 400 grains and it got away.....now he shoots 500 grains." Look, if you really think that even a huge difference....100 grains....is going to make a difference in kill vs no kill in a bad shot you are crazy.....it is mostly an excuse for a poor shot.
Joe
i will leave it alone, but shooting huge cut EXPANDABLES rob a huge amount of penetration as well.
Joe
Ouch.
You are completely correct.
But ouch.
If loosing or gaining 100 grains in arrow weight was not a big deal (starting at 350 grains), then someone should shoot a 250 grain arrow against a 450 grain arrow and see how the tests come out.
I'm thinking that 100 grains is gonna make a big difference in that test.
I am not saying heavy arrows are bad, i am just saying it isn't necessary to start over with your set up just because some guy says so.
I am not saying i am right, i am just a big fan of shooting a well tuned, fast, sharp, efficient coc head rather than beefing up my arrow. thats all
Besides my indoor arrows are somewhere around 750 grains.....and i shoot the lights out with those babies....so i guess i do know how to set up a heavy arrow huh?
Joe
Joe
I shot 350-400 grain arrows for a few years, and I killed a bunch of animals with that arrow weight. I now am shooting a heavy arrow (for about 6 years), and the overall damage and penetration is much better with my heavier arrows. So I agree with you 100% about an animal will die with a lighter arrow, BUT I don't agree with you on the statement about 100 grains not making a big difference.
So shoot whatever you like best, but calling someone crazy about 100 grains not making a difference is...well....not making any sense to me.
Joe
http://archeryreport.com/articles/
These are not deer. And it's been proven time and time again, light weight does not retain energy though initial impact (penetration) nearly as well as heavier weights. Or trad guys would be going to lighter and lighter arrows and wind up with better penetration.
Honestly, the only reason I could think of for anyone actually ADVOCATING a 350 arrow for elk is they think they are going to be forced to make 70, 80, 100 yard shots on elk, as was mentioned earlier in a few posts. You really want to debate that?
I have debated with elk "experts" that have even told me you can shoot farther at elk because they have a bigger kill zone. IMO that is not true in the real world. In the real world you have to make a very good shot on elk or you are in for a very long day. Or three. Not they might go a few hundred yards, or into the next field, they may go a few miles over a few days. I've seen it personally with fairly decent shot placement.
Even the rifle guys put the 243s and the 25-06 back in the cabinet and pull out the 300 and 338 mags in elk season. Must be a bunch of morons, don't they know they could just use their deer rifles?
I can't wait to hear what some folks recommend for cape buffalo. After all KE is the answer, speed the equalizer. Unless of course you get into the real world of BIG game penetration where weight is master.
I agree as would most guys who know would....that speed is not the key, KE is far from being the key (due to adding speed and loosing weight gives the same KE...BUT LACKS MOMENTUM), and what brand bow means crap...unless you use a Mathews...they kill by making elk just die of fear!!!.lol
What many here are saying is simply this...two bows shooting the same KE and one has a much heavier arrow.....penitrates much better.
Thats it.
Autumn_Archer's Link
I teach IBEP/Bowhunter ed, and I use this analogy when it comes to arrow weight. Picture a small car, traveling at 70 mph, crashing into a house.
Next, picture a large delivery truck, traveling at 50 mph crashing into that same house.
Which one might you think would take longer to slow down from its speed of travel before coming to a stop? And how far into that house would it go?
It is a simple rule of physics. Many get hung up on kinetic energy, but the real determining factor in penetration is momentum. A heavier arrow simply has more momentum, and will have far more penetration potential. We all know that the further the shot, the higher the odds of "perfection" going out the window. Animals move. Arrows hit unseen obstructions to its flight path. We make a less than perfect release. So why, in fairness and respect for the animal we pursue, would we shoot an arrow that pushes the limit as far as light weight?
I've read studies done by Dr.Ashby who has extensively tested penetration and arrow flight characteristics. These were done with traditional archery gear, but the physics remains the same regardless of bow type. Once the arrow is released, the physics of its flight, momentum and ability to penetrate arethe same. The only difference is arrow speed.
I will say that if you do read these, they are dry reading. But, you will learn a tremendous amount of info concerning arrow weight, penetration, broadhead design, and arrow setup such as FOC.
I shoot a 620 gr arrow, with 200 gr at the tip from my 57# longbow. I can tell you my arrow isnt gonna break any sound barriers. My bow is dead quiet, my arrows fly like darts, and when they hit, they hit hard, and pentrate deep.
Here are links to his studies. The first one is an article written about Momentum, Kinetic energy and Arrow Penetration. Its dry reading, but very informative and educational.
http://www.tradgang.com/ashby/Momentum%20Kinetic%20Energy%20and%20Arrow%20Penetration.htm
The 2nd link is to the entires series of his studies. There are several.
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=forum;f=24
As responsible bowhunters, we should always strive to make sure our setup is adequate for the game we pursue. Razor sharp broadheads on a properly tuned arrow/bow combination, accurately placed, and taking responsible shots to ensure quick clean kill shots. We owe that to the animals we hunt.
TD - Put an FMJ in the 22-250 and watch it zip through any elk, minus the heavy bone of course.
A couple things I would consider strongly is the durability differences between light and heavy arrows. Elk are way tougher than deer, don't let anyone tell you any different. I have seen good shots turn into 5 mile tracks. I want 2 holes on every elk I shoot and weight is the best way to accomplish this. You can go up in poundage but why shoot a weight you can't handle well? You are just asking for trouble.
Lighter arrows can do the job if conditions are right or even just good, but I personally don't prepare for good conditions I prepare for the worst and practice for the best. Elk are my favorite big game animal and I owe them all the respect they deserve.
Just another side note and this will vary from bow to bow and setup to setup but there is often less difference in trajectory by dropping to lighter arrows than you may think. On multiple setups I have found that with light arrows at longer distances my pin gap was actually wider with the lighter arrows. They were narrower closer up but not at distance. I switched back to my heavier arrows and haven't looked back. This was only a 125g drop but it shows that if you are looking to go light weight just for a trajectory advantage you may not be gaining much if anything.
The Dr. Ashby articles are very informative if you really want to learn from a gent that has spent decades and 100's of animals studying this stuff. People here talk of scientific proof vs anecdotal evidence. We are all anecdotal compared the the massive amount of information he has compiled.
This link is to one of his short explanations of what makes his idea of a perfect arrow. http://www.alaskabowhunting.com/PR/ATA_Handout_Text_Web.pdf
Hope this Helps!
momementum
"People who shoot lights out all time,stay in dark" "Animal touched by heavier/slower become lighter/faster"
"Bigdan pull posts faster than Woody pull punches"
"Toto bless rain and Ashby in Africa"
Great summation!!!!
If you have not hunted and killed elk then I would consider the opinion as conjecture. I work for the Army and have supply subject matter experts routinely on a myriad of weapon systems and tactics, techniques, and procedures and it amazes me how quickly that they can kill an accepted opinion with real combat expertise.
Sorry for the rant but this has been bothering me a great deal on some recent threads.
Have seen a lot of issues with expandable broad heads and light arrows off super hot compounds that resulted in no elk.
As far as "KE" goes, it all boils down to how hard you want your bow to work to send the arrow down range and 100 gr broadheads are just fine...
