I am planning on deer hunting with my AR 15 this year. I think that I have heard that a 62 grain bullet is the heaviest you could use in a 1/9 twist rifle. I found some 69 grain BTHP cheap (Remington ammo 50 for 29.99). It is match grade ammo and I was wondering if my AR with the 1/9 twist would be ok out to 100 yards? As always, any help would be greatly appreciated.