I want to buy some 308s. I don't know enough about it. I understand hollow points, and what they do. I figure FMJ will penetrate better. Seems these Fed 168 BTHPs are real accurate and good. But, what kinf of advantages or things will the fmj do at distances, that the HP won't. What type of objects or while experminting, have you guys seen a difference in one will do, that the other won't?? At what distances would you say one would or wouldn't penetrate vests etc. ??