In this thread Iíve been discussing buying a 9mm for my girlfriend, most likely either a Sig P239 or a Glock 26. Both have a 3.6 inch barrel. My experience with the 9mm is limited to the M9 (Beretta 92) using military FMJ ammo. (I carry either a .40 S&W or a .357 Mag)
So assuming we buy either firearm with a 3.6 inch barrel, which bullet weight will perform best for self-defense?