Heckler and Koch HK-416 chambered for the 5.56mm NATO cartridge. The 416 is up there as one of the most reliable NATO rifles in service, with incredible gas tubing and an upper receiver made to last in dirty conditions. In addition, the 5.56mm rifle gives a good rate of fire with accurate semi-automatic fire and minimal bucking, plus steel-core armor piercing rounds give some extra penetration while maintaining sufficient stopping power from hydrostatic shock effects to take a man down at range with a single shot. Basically, I have a weapon that I can lug around with me and whip out to defend ma girl at a moment's notice.
