Bushmaster XM15-E2S Multi Lower Matte Black

FMK Firearms AR-1 Blue 5.56 NATO / .223 Rem Stripped Lower

American Defense UIC Stripped Lower 5.56/.223

Battle Arms Development Workhorse Stripped Lower Receiver .223 Remington/5.56 NATO

Spikes Tactical Enhanced Lower Parts Kit Black .223 Rem / 5.56 with ST Battle Trigger

FORTIS LICENSE GEN II AR15 LWR STD

Rise Armament Stripped Lower Receiver Black 5.56

Radian Weapons A-DAC 15 Complete Lower 5.56 / .223 Rem w/ SBA3 Brace