5.56x45mm NATO Upper Receivers

Anderson Manufacturing AR15-A3 Stripped Upper Receiver with Parts Kit

Aero Precision Threaded PRO Complete Upper, 16.3\" 5.56 CHF Mid-Length Barrel with 15\" ATLAS R-ONE M-LOK Handguard - Kodiak Brown Anodized - APUG700401M103-1

Aero Precision M4E1 Threaded PRO Complete Upper with 16.3\" 5.56 CHF Mid-Length Barrel and 15\" ATLAS S-ONE Handguard - Anodized Black - APUG700105M103-1

Aero Precision Enhanced PRO Complete Upper, 16.3\" 5.56 CHF Mid-Length Barrel with 15\" Enhanced M-LOK Handguard - Anodized Black - APUG600218M103-1

Aero Precision M4E1 Assembled Threaded Upper Receiver, Special Edition: Thunder Ranch FDE Cerakote - APAR700219AC

Aero Precision - M4E1 No Forward Assist Assembled Upper Receiver - 16\" Barrel - .223/5.56 - APAR612218M7

Ar-15 Stripped Upper Receivers - Ar-15 Stripped Upper Receiver No Auto Sear/Forward Assist

Ar-15 Upper Receiver Assembled No Auto Sear Cut - 5.56mm Assembled Upper Rcvr No Auto Sear Cut For Ar-15 Fde

M4e1 Superlative Arms Piston Complete Upper Receiver Groups - Piston Upper 10.5'''' Barrel 9'''' Handguard Blk