5.56x45mm NATO Receivers

M4-L89 5.56x45 Nato Assembled Upper Receiver - M4-L89 5.56x45 Nato 11.5''''bbl 10.75'''' L89 Rail W/Nox9

M4-L89 5.56x45 Nato Assembled Upper Receiver - M4-L89 5.56x45 Nato 10.5'''' Bbl 9.75'''' L89 Rail W/Nox9

M4-L89 5.56x45 Nato Assembled Upper Receiver - M4-L89 5.56x45 Nato 14.5''''bbl 13.75'''' L89 Rail W/Nox9

Dark Storm Industries DS-15 Bolt Action 5.56x45mm NATO 16in Upper Kit Full Kit 1-7 Twist Anodized Black

M16 R0901 5.56 Complete Upper Receiver Groups - M16 Upper Group 20in M16 Handguard Stripped

M16 R0901 5.56 Complete Upper Receiver Groups - M16 Upper Group 20in Moe Stripped

M4 5.56 Upper Receiver Groups - M4 Le6933 Upper Group 11.5'''' Stripped

M4 5.56 Upper Receiver Groups - M4 Le6921 Upper Group 14.5in Stripped

Colt Monolithic AR-15 Pistol Complete Upper Receiver 5.56x45mm NATO 14.5" Barrel

PRI Mark 12 Mod 0 AR-15 Complete Upper Receiver 5.56x45mm NATO 18" Barrel 1:8" Twist Flat Dark Earth

Brn 16a2 Upper Receiver - Brn-16a2 5.56x45 Nato 20'''' Bbl Upper Receiver

Brn-16a4 Complete Upper Receiver - Brn-16a4 5.56x45 Nato 20'''' Bbl Upper Receiver

Brn-773 Upper Receiver - Brn 733 C7 5.56 Upper Receiver, 11.5'''' 1-7 Twist Black

Brn-601(R) Retro Complete Upper Receiver - Brn-601 5.56mm 20'''' Bbl Upper Receiver

Brn-4(R) Complete Upper Receivers - Brn-4 5.56mm 10.4'''' Heavy Bbl Complete Upper W/9'''' Handguard

Brn-4(R) Complete Upper Receivers - Brn-4 5.56mm 10.4'''' Med Bbl Complete Upper W/9'''' Handguard

Brn-4(R) Upper Receiver Assemblies With Chrome Lined Barrels - Brn-4 Assembled Upper 14.5'''' Heavy Chrome Lined Barrel Black

Brn-15 Upper Receivers 5.56mm Nato - Brn-15 5.56mm 11.5'''' Bbl .750'''' Gas Block Upper Receiver

Brn-15 Upper Receivers 5.56mm Nato - Brn-15 5.56mm 16'''' Bbl .625'''' Gas Block Upper Receiver

Brn-15 Upper Receivers 5.56mm Nato - Brn-15 5.56mm 16'''' Bbl .750'''' Gas Block Upper Receiver

Brn-180s(R) Gen2 13.9/14.5 223/5.56 Complete Upper Receiver Assy - Brn-180 Gen 2 13.9'''' 223 Wylde Upper Receiver Assy Black

Brn-180s(R) Gen2 13.9/14.5 223/5.56 Complete Upper Receiver Assy - Brn-180s Gen 2 14.5'''' 223 Wylde Upper Receiver Black

Ar-15 Mike-15 Gen 2 Upper Receiver Assembly 223 Wylde - Ar-15 5.56/223 Wylde 13.9'''' Gen2 Upper Rec Forward Charging

Kexuan Aluminum Receiver End Plate w/Dual Sling Clip Type Adapters for .223/5.56/.308 Buffer Tubes Dark Blue