VTbowman Posted August 26, 2005 Report Share Posted August 26, 2005 I posted this link in another post but feel its well worth a good read to see the information Dr. Ashby has put together concerning penitration and all its factors. His research spans well over 20 yeras on this one subject and has preformed about every test known to man to prove his research. Some is very technical and he has a lot of graphs that mean little to me. But his work is well respected and as far as I know there has been no one else to even come close to this scale of research for bowhunters. Please take the time to read threw some of his work. http://www.tradgang.com/ashby/ This information is very valuable so maybe a mod can pin this on top for a while, or longer. Thanks Quote Link to comment Share on other sites More sharing options...
VTbowman Posted August 27, 2005 Author Report Share Posted August 27, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... ttt Quote Link to comment Share on other sites More sharing options...
willfish03 Posted August 27, 2005 Report Share Posted August 27, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... its nice reading and technical. but helocopters and bumble bees technicaly cant fly. to say a light arrow cant penitrat like a heavy arrow only needs to go to the range or field. i have never got the penitration i get with a light arrow from a heavy arrow. 9 kills in 2 seasons, all complete passthrough's Quote Link to comment Share on other sites More sharing options...
VTbowman Posted August 27, 2005 Author Report Share Posted August 27, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... [ QUOTE ] its nice reading and technical. but helocopters and bumble bees technicaly cant fly. to say a light arrow cant penitrat like a heavy arrow only needs to go to the range or field. i have never got the penitration i get with a light arrow from a heavy arrow. 9 kills in 2 seasons, all complete passthrough's [/ QUOTE ] My biggest gripe about the entire thing is that the word "penitration" should not be a term used with compounds or thier abilities. I agree the whole concept is moot when your talking about that much speed, energy, and momentum. Dr. Ashbys research is based on traditional equipement for the most part. When only given so much speed and energry, thats when momentum plays the key role and then the broadhead design too. I must admit I aint gonna be chuckin no 700 to 900 grain arrows at deer either. LOL Quote Link to comment Share on other sites More sharing options...
PAbowhunter4life Posted August 28, 2005 Report Share Posted August 28, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... Here is my biggest beef with this whole topic lol. For YEARS pros and archers such as ourselves went off of the KE equation alone. We produce x amount, we have enough energy to kill this animal and this, and so we did. People have been blowing light weight arrows through Moose, Elk, Grizzly, African game etc. for years just going off of the KE factor. Now all of the sudden another report comes along that says momentum is the ultimate factor, don't worry about KE. So what, you're telling me is all the people pros and ams alike that have been blowing light shafts completley through big game animals for years were just getting lucky??????????????? I DON'T BUY IT ONE BIT!!!!! Like VT said, if you are shooting a recurve bow or even a childrens bow that is very slow by todays standards then YES, a heavier arrow will definitely penetrate better that a fast moving projectile. But with todays equipment moving a 406 grain arrow at 280 fps and producing 70 lb of KE, it becomes a simple matter of how far do you want the arrow to penetrate the tree after it goes through the elk???? Quote Link to comment Share on other sites More sharing options...
AJ Posted August 28, 2005 Report Share Posted August 28, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... [ QUOTE ] For YEARS pros and archers such as ourselves went off of the KE equation alone. ...People have been blowing light weight arrows through Moose, Elk, Grizzly, African game etc. for years just going off of the KE factor....Now all of the sudden another report comes along that says momentum is the ultimate factor, don't worry about KE. So what, you're telling me is all the people pros and ams alike that have been blowing light shafts completley through big game animals for years were just getting lucky??????????????? [/ QUOTE ] If you called a duck a frog for years and years it does not make it a frog, it's still a duck. Who cares what they called it. Their setup still produced adequate momentum to drive the arrow through the vitals. An arrow kills by hemmoraging. Slicing blood veins and arteries to allow the animal to bleed out, causing the central nervous system to shut down due to lack of oxygen. A bullet kills by inducing shock to tissue. This will also cause bleeding and disrupting of the central nervous system. If you can kill a ___ (fill in with whatever animal) with a blunt tip you indeed have enough energy. Since you install a broadhead on the arrow, it will cut a hole that is much larger than the arrow, allowing the shaft to pass much easier through the tissue. You are now starting to get into an area with a lot of variables. Heavy vs light, arrow composition (carbon vs aluminum), shaft diameter, length vs weight, arrow speed, broadhead size, target composition (deer, elk, moose, etc) , and probably more things will all have input in the equasion. There probably is a best case setup but I don't care enough to even try to do the testing to see what it is. There are a lot of setups that work. If you are happy with your setup, fine, enjoy it. Quote Link to comment Share on other sites More sharing options...
VTbowman Posted August 28, 2005 Author Report Share Posted August 28, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... [ QUOTE ] with todays equipment moving a 406 grain arrow at 280 fps and producing 70 lb of KE, it becomes a simple matter of how far do you want the arrow to penetrate the tree after it goes through the elk???? [/ QUOTE ] This is why I cringe when I hear compound shooter talk about "penitration".. Its a moot point. 100% penitration is nothing more then pass threw. But try this. Take that 280 fps bow with that 406 g arrow and add about 50 or even 100 grains to the arrow. Shoot it threw a chrono. Obviously your speed with drop some. However what is your KE? Roughtly the same. Dont believe me? Try it. I did and was amazed..... Now work the numbers for MO with arrow #1 at 400g and then arrow #2 at 500g. The MO raises dramtically. But in the end you need BOTH the MO and KE to get arrow "penitration" results. KE just seems to be the term the "market" uses as a catch phrase. Not thats it wrong but its NOT the poster child of penitration. Dr. Ashby reports shows the the factor of MO plays a larger role, not the only role. JMO. Quote Link to comment Share on other sites More sharing options...
BowJoe Posted August 28, 2005 Report Share Posted August 28, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... I once wrote a letter to Bow and Arrow Magazine and they printed it. The letter concerned a test in which several arrows and several broadheads were tested on pieces of plywood set a few inches behind eachother to show the differences in penetration. My Letter was a simple point. Deer, nor any other game animal for that matter, are made of plywood. They are made of a soft flesh no matter the size and can be penetrated as long as the shot hits where intended and the arrow flies true. By true, I mean that the arrow is not fishtailing, flying tail up or down or being off-set by any other means. Also, a "Clean Pass Through" is something desireable if the hit is marginal at best because any hit with a pointed edge through most vital organs results in a death within a short time. A shot to the heart (Bon Jovi) is fatal everytime.<------Period. A shot to the lungs is also a pretty good bet as well. If you can't breath you can't run. But if you only get both lungs and not a clean passthrough, that is still a dead animal!!! Quote Link to comment Share on other sites More sharing options...
Leo Posted August 28, 2005 Report Share Posted August 28, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... [ QUOTE ] But try this. Take that 280 fps bow with that 406 g arrow and add about 50 or even 100 grains to the arrow. Shoot it threw a chrono. Obviously your speed with drop some. However what is your KE? Roughtly the same. Dont believe me? Try it. I did and was amazed..... [/ QUOTE ] Yep, I absolutely believe you. I have heard many archers say they are going to a lighter arrow to increase their K.E. It doesn't work that way. Think about it. Going to a lighter arrow creates more energy??? Going to a lighter arrow gets you a faster arrow. But not really much more energy (if any). The only reason the K.E. isn't exactly the same is because the mechanical efficiency of your bow varies with arrow weight. Mechanical efficiency of your bow is the (Kinetic Energy of the arrow)/(Potential energy stored in the bow) If you really want more Kinetic Energy, turn up the draw weight. This increases the potential energy in the bow available to be turned into Kinetic energy when the arrow is released. Quote Link to comment Share on other sites More sharing options...
ThethirdI Posted August 28, 2005 Report Share Posted August 28, 2005 Re: MO and KE??? Then read Dr. Ashby Reports.... Refer to my posting called Aluminum fixed wing penetration in the Bowhunting forum and that's all I have to say.... Quote Link to comment Share on other sites More sharing options...
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