Heckler & Koch MR556 A4 Upper Receiver Kit with 16.5-inch Barrel, Black

Heckler & Koch

Radian Weapons R0473 Flat Dark Earth 16-Inch 1:8 Barrel 223 Wylde Upper

RADIAN WEAPONS

Geissele Automatics GEI08-159 URG-I Upper Receiver in Desert Dirt Color with 14.5-inch Barrel</Title>

Geissele Automatics

Radian Weapons R0628 Radian Upper and Hand Guard Set in Olive Drab Green

RADIAN WEAPONS

Lantac Recon Upper Receiver Group for 223 Wylde, 16-inch Barrel - Black

LanTac USA LLC

Steyr Arms AUG 9x19mm Police Training Conversion Kit – 16-Inch Threaded Barrel, 28-Round Magazine

Steyr Arms

Savage Arms Single Shot Adapter for Axis & 110 Models - Model 56306

Savage Arms

Luth-AR A1 Complete Upper Receiver – Black Anodized for Retro M16 Builds

Luth-AR

Battle Arms Development WORKHORSE 556 Upper Receiver - 16 Inch Black for .223 Remington

BATTLE ARMS DEVELOPMENT

Battle Arms Development WORKHORSE 16-Inch Upper Receiver in Black for 5.56 NATO

BATTLE ARMS DEVELOPMENT

TROY Industries AK47 Railed Top Gas Tube with Picatinny Rail in Black, Part SRAI-AK1-T0BT-00

TROY Industries

Rock River Arms Tactical Carbine A4 Mid-Length Upper in .450 Bushmaster, 16-Inch Barrel

Rock River Arms