5.56x45mm NATO Upper Receivers

Qrb Upper Receiver Takedown Kits W/ Law Folding Adapter - Qrb Upper Takedown Kit Mid-Length W/ Folding Stock Adapater

Brn-4 Piston Upper Receiver Kits - Brn-4 10.4'''' Upper Receiver Kit W/ Medium Profile Barrel

Brn-4 Piston Upper Receiver Kits - Brn-4 16'''' Upper Receiver Kit W/ Medium Profile Barrel

Brn-4 Piston Upper Receiver Kits - Brn-4 14.5'''' Upper Receiver Kit W/ Medium Profile Barrel

M4 5.56 Complete Monolithic Upper Receiver Groups - M4 Le6940 Upper Group 16in Stripped

Mk18 Block Ii Tribute Bundle

Brn-4(R) Blem Upper Receiver Assemblies With Nitride Barrels - Blem Brn-4 Assembled Upper 14.5 Md Black Nitride Bbl

Ar15a4 Upper Rcvr, Flattop, Mod. Carb

Ar15a4 Upper Rcvr Assembly, Carbine

Aero Ar-15 Assembled Upper 5.56mm Build Kits - Build Kit 5.56mm Assembled Upper 16'''' Carbine 12'''' Hg Black

Aero Ar-15 Assembled Upper 5.56mm Build Kits - Build Kit 5.56mm Assembled Upper 16'''' Mid-Length 12'''' Hg Black

5.56mm Complete Upper Receiver W/Brn Bolt Carrier Group - 5.56mm 16'''' Bbl M4 Comp Uppr Rcvr W/Brn Bcg & Charge Handle

Ar-15 Forged M4 Upper Receiver 5.56mm - Ar-15 Forged M4 Stripped Upper Receiver

East India 5.56x45 Assembled Upper Receiver Starter Kit For Ar15 - East India 5.56x45 Assmb Upper Medium 16'''' Bbl W/Rail & Fsb

East India 5.56x45 Assembled Upper Receiver Starter Kit For Ar15 - East India 5.56x45 Assembled Upper Medium 10.5'''' Bbl W/Rail

Dirty Bird 20" M16A1 Enhanced 5.56 Retro Upper Assembly - No M4 Feed Ramps

M16A1 Assembled Upper Receiver - Without M4 Feedramps

M16A1 Stripped Upper Receiver - Without M4 Feedramps

Dirty Bird 16" Side-Charging 5.56 NATO Govt M-LOK Complete Upper

14.5" Pin & Weld 5.56 Mid-length Magpul MOE SL AR15 Upper

Dirty Bird Industries 7.5" 5.56 DRP Pistol M-LOK V2 Upper Assembly

Dirty Bird 10.5" Government Carbine 5.56 M-LOK Upper Assembly - V3, OD Green

Dirty Bird 10.5" Government Carbine 5.56 M-LOK Upper Assembly - V3, FDE

Dirty Bird 10.5" Government Carbine 5.56 M-LOK Upper Assembly - V3, Black