That's a good idea. And, as long as you hunt nothing larger, tougher or meaner than whitetails, I guess it's plenty valid. However, since hunting shots don't exceed 30 yards in most instances, trajectory is extremely overblown. In my opinion, since aflatter trajectory is practically meaningless at 30 yards and less, it's best to use that excess energy to give yourself a surplus of penetration potential for those times when 'just in case' comes into play.

Say the arrow hits a small, unseen twig before it gets to the critter. The lighter, faster arrow will be deflected further off course than the slow one. The perfect heart shot could turn into a perfect gut shot with a light arrow while the heavy one might still get lungs/liver.

Say the animal spooks and spins at the shot, and that perfect broadside shot turns into a rump shot. Where you needed only 18" of penetration into ribs and organ tissue to bury up in the mud on the other side turns into a situation where you might need 30" through heavy, dense muscle, guts, stomach and diaphragmjust to get to the vitals. The light arrow might not retain the 'punch' to do the job.

SurelyI am not the only one who is afflicted by Murphy's Law when I'm hunting!

If you haven't read Ashby's first study and seen his reports on his current research,and if you can keep an open mind about something you read on a traditional website - I've learned that some people don't have the intellectual capacity to do so - you might find it some interesting reading. Might even modify your thinking about how much 'punch' a high KE light arrow actually has vs a heavy arrowat much less KE.

I would highly recommend it asrequired reading fortraditionals but alsoanyone who shoots a bow on the light end of the KE scale, or wants to hunt very large animals with a bow, or just wants to know how to use arrow weight and broadhead selection to get the most deadly arrow possible from his setup.

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=forum;f=24

Actually, what I said is "valid" regardless of the animal. No getting around the fact that energy expended in the ground after passing through ANY animal is energy wasted. It is of course obvious that some animals require more ke/momentum to achieve pass through than others but the principle still holds.
Arrow weight alone is definately not the only consideration here. As you have pointed out many times, it is momentum which results from both mass and velocity that is the key to resisting deflection and increasing penetration. If the lighter faster arrow is carying more momentum as is the case with the 301 ft/sec 347 grain arrow vs the 221 ft/sec 600 grain arrow then the lighter faster example will actually penetrate more and deflect less. Only looking at arrow weight is very misleading. There's a little more to it than that! If you read Dr. Ashby's papers carefully you will see that it is momentum that is key.
I'm not sure where you are trying to go with this Arthur. Maybe I'm wrong but I thought you agreed that a 600 grain arrow at 221 ft/sec was adequate for "the job". I've seen you write many times that traditional archers have been taking every North american big game animal with this combo for years haven't they? In our comparison, the 347 grain 301 ft/sec combo is delivering both more KE and momentum and therefore more punch by any measure than the heavier arrow example.

I had kinda hoped you would takesome time to read the study reports before responding, Sylvan. You would have known. Real world data always trumps theory, ya know.

I have read them Arthur and if you had taken the time to read them more carefully I would not have had to correct you. Take care!

I'm about to read that artice but I was just wondering with a bow with a draw of 60# and 29" lenth shooting at around 260-270 and a 370g arrow after how many yards will I start to lose accuracy after if I want to shoot a single pin? Didn't want to make a new thread about it and clutter the forums.