What is the best way to determine proper arrow weight?
 

I am shooting at 72lbs at 29" and my arrows are cut to 28.25" my arrow weight at this time is 294gr. + 75gr. broadhead for a total of 370gr. / 72lbs = 5.13 grains per pound of peak weight my arrow flight is good but I don't want to shoot under weight, and cause damage to my bow. I was always told that peak weight x 5gr. was the way to pick arrow weight, is this correct should I shoot a heavier or lighter arrow? I do plan on moving up to 100gr. broadheads next year to gain a wider cut I shoot muzzys and the 100gr. are 3/16th of an inch wider than the 75gr.Anyone got any suggestions!

I always try to stay just above 5gr per lb of draw weight but i like speed.Some people like to go heavier just a matter of opinion but never under 5grs per lb.

To a point you can't get too heavy an arrow IMO but there is no stead fast rule except that in order to stay within warranty your arrows must weigh 5 grains per pound of draw weight.

For hunting purposes a heavy arrow is more desirable with few exceptions.
*A bow firing a heavy arrow is quieter which is less likely to cause a deer to "jump the string".
*A bow is more efficient at launching a heavy arrow so the heavy arrow starts out with more Ke and momentum than a light arrow and it maintains its speed over distance better than a light arrow. This all equals better penetration from the heavier arrow.
*A bow firing a heavy arrow is less likely to have a failure due to more of the bows stored energy being transferred to the arrow instead of being absorbed by the limbs and riser.
*A heavy arrow is less effected by crosswind (all other things being equal)

For example.......
Arrow A weighs 350 grains and leaves the bow at 300 fps. It will loose 22 fps and 10 foot pounds of Ke over 70 yards.

Arrow B weighs 500 grains and leaves the same bow at 260 fps. It will loose only 13 fps and only 7 foot pounds of KE over 70 yards.

Very good advise right there!

All I will add is to consider the game your after. Deer sized and under a 350 grain arrow (i'm assuming 70# draw weight) will blow through them easily with nearly any broadhead and good shot placement.

Going for elk, moose or larger bear, go heavier. Say 400-500 grains. It will help with penetration on the larger, heavier boned animals.

Bigger then elk or dangerous game go 500+ grains or a .416 Rigby ;)

Choosing arrow weight is more preference than science

There is a curve where you can absorb near maximum energy while still maintaining decent speed. You'd have to plot that out on a chart shooting different arrows through a chrono, or you could use a program like OnTarget2, and it will do it for you to some extent. For me, I'm shooting a 445gr arrow out of a 71# bow. That arrow is zipping out there around 286fps, not super fast, but it hits REALLY HARD in comparison to what a 350 arrow would.....:happy0001:

And I agree with most everything Bigbulls said, especially the energy absorbed by the arrow vs. the energy absorbed by the bow. I believe if you took an HONEST poll of guys who'd had a limb failure, you'd find that at least 75% of them were shooting LIGHTER arrows, less than 6gr/#, and some less than 5gr/#. Speed kills alright, but unfortunately, sometimes all it kills is your bow!!!!

Thanks for all the impute,I am not really concerned with speed I'd rather have a slow hit than a fast miss! And I think I'll try a heavier combo since you do loose less KE and less speed plus less effect by crosswind there fore maybe more accuracy and less bow wear. Thanks

I have been shooting the Axis arrows and are 9.2 gr per-heavy. I shoot 70 lbs and slick trick 100 gr bh. The new bows are a lot faster and you can get lighter. My new rig, being built now, has one shooting at 51.7lbs 345fps with a 6gr per. He used the proto type on an Elk and got complete passthrough. I never not had a complete passthru even at a doe this year at 38 yds and hit the spine, thought it was further. Shot a buck at 12 yds thru the shoulder blade and thru the femur bone on the other side and stuck in the dirt. That is why I like the heavier shafts, but spine is just as important. With my new rig I will be shooting tapered shafts and they will be lighter, with more FOC.