I have always shot and carried FMJ 9mm. I'm not sure why, I just always have. Recently I read something that reminded me that hollow point ammo has less chance of going through the target and possibly hurting someone else.
Of course I know that I should always be aware of what is behind the target I'm shooting at, but in a life or death self defense situation I can envision that a shot could be taken where and innocent bystander could be in danger of being shot if the round went though the target. Is the difference between FMJ and HP enough to warrant carrying HP for that reason alone ?