I have in my readings all over the web encountered one dearly held belief among all traditional bow hunters. For adequate penetration on deer sized animals your arrow needs to weigh a minimum of 10 grains per pound of bow weight you are shooting. So for example my 50lb recurve needs to be flinging at least a 500 grain arrow. Now I fully understand that heavier arrows have some advantages. They can quiet your bow, adsorb energy more efficiently and carry more momentum than lighter arrows. That's not the debate or question I'm trying to get at here.

Here's what I don't understand. I have seen guys who stated their intention to hunt deer with a 400 grain arrow out of a 50 or 55lb recurve bow at traditional bow hunting forums just get jumped like they announced they were going to go hunt bull elephants with a BB gun. Waaaaay too light. You'll regret it. Fool's folly. Etc, etc,. Clear violation of the 10 grains per pound rule. 15 yard penalty and loss of down.

And yet in these same forums some guy will invariably come on there and ask if a 40 lb recurve is powerful enough to kill deer. And the answer is a universal "yes" as long as he sticks to the 10 grains per pound arrow weight rule.

Ahhh, but there's the rub. A 10 grain per pound arrow out of a 40 lb bow is a 400 grain arrow. So how in the hell can a 400 grain arrow out of a 40lb bow be perfectly adequate for deer while a 400 grain arrow out of a 50lb bow is irresponsible and doomed to give inadequate penetration? From equal draw lengths the 400 grain arrow from the 50lb bow has got to be moving faster than the one from the 40 pound bow. How can it not out perform the slower arrow of the same weight?

Can anyone explain that to me?

i'm not in the traditional bow hunting scene but sounds to me like it's a stupid rule to go by. I would much rather calculate the kinetic energy and stick to a minimum kinetic energy. Sounds like that rule doesn't take draw length, arrow speed, etc into the equation.

It's hard enough to arrow a deer with modern equipment. Then you have to hunt for deer you have shot most of the time. I think modern equipment is enough of a challenge for me.

It started as a recommendation then became a "mandate." Most of the ones mandating it have no idea what KE, Momentum or anything else actually means. There's several RULES in Trad archery that started out as recommendations. A heavy arrow penetrates better, but I'm sure there is a break even point.

I'd try but you are just looking to stir some chit over something you already have yer mind made up over...

I've seen the "kinetic energy vs momentum or cast and how it all relates to penetration" debates until my head hurt.

I had successfully, totally forgotten about them until this thread...thank you

Bottom line is shoot what flys good for you and put it where it needs to be and remember your bow will appreciate a heavier arrow, the noise will be reduced and you'll get better penetration and a deer will absolutely jump your string

I'd just stick to the traditional aluminum.

Sorry, Todd, I've got no idea on your question. It does seem logical to ask.