My cousin’s grandson finished up basic in the Army and now he’s onto the next phase of training, forgive me I don’t know the lingo. He’s in Airborne. Anyway the Army now shows training pictures on their Facebook page. As it happens he was in one recently. They were teaching them how to clear rooms in teams and squads. So to my question: why do they use an M4 for that? Seems awkward and unruly inside a building with a real possibility of over penetration. Wouldn’t a 9mm SMG of some kind be better, or a handgun or shotgun?