In case there was any confusion as to why Gordon was able to use pistol ammo for the M16
Department of Energy Colt SMG
My understanding is this rifle is a M16 with a modified buffer, bolt, magazine well, and barrel converting the rifle from a gas operated bolt action rifle to a Blowback action pistol caliber Carbine perhaps chambered in 9mm any automatic pistol cartridge would fit the bill .40 SmithWesson or .357 Sig maybe .45AARP
40mm Grenade launcher and .40SW is a vibe for sure
Also Im not really a fan of the MP5












