9mm rounds can penetrate 3A body Armor if you have high enough velocity. The 9mm Extreme Defender in 68 gr +P can get over 2000 fps out of a carbine style weapon, the normal barrel length will be 16". This is my normal 9mm carry load and I use it in in my handguns and some SBR or carbine guns. I still prefer the Hornady Black SBR ammo, 75 gr at app 2100-2200 fps, but Underwood makes some fantastic rounds for hunting and self defense.