I am a Deputy Sheriff and carry a Bushmaster shorty carbine in 556/223 at work. It has the 14.5" barrel that is thicker than normal with a 1/9 twist. It is pretty much up to us what we carry for duty ammo. Right now I'm carrying 55 gr. Federal ballistic tips. Does anyone have any information on what ammo my gun could shoot that has a good track record of stopping attackers? Could I shoot heavier than 55 gr. bullets out of this barrel and be ok? I'd like to use 62 gr. or heavier SP, HP, or ballistic tip bullets if the gun will stabilize them.