I use it in my 270 (130 gr)for deer, my son uses it in his 30-06 (150 gr)for deer and my daughter uses it in her .243 (100 gr)for deer. I shot a deer two weeks ago head on at the base of his neck / brisquit with the 130 grain .270 bullets. The bullet entered his chest, blew about half the heart off, turned the lungs to jelly (the only parts of the lungs that were recognizable I could hold in one hand), through the stomach, through the intestines and stopped just under the skin right above his penis. I recovered teh bullet and it weighed 98 grains for 75% weight retention. It mushroomed back to the cannelure and stopped. I know this is but one example but pretty dang good performance if you ask me.

The next weekend my daughter shot her first buck in the spine and obviously dropped the deer right there. That bullet was not recovered, although we did find one small fragment of lead in the meat.

AS for the rate of twist goes, a 165 bullet may or may not be the best shooting bullet out of your rifle and a 165 grain bullet does not correlate one bit to being the best weight fora 1 in 10 twist barel. The twist needed in a given barrel is determined by the length of the bullet for a given caliber and velocity at which that bullet will be traveling... NOT the weight.A 30-06 with a1 in 10 twist will stabilize bullets up to about 200 grains... give or take, depending on what bullet is being used.