Centurion Arms CM4 5.56 Forged AR-15 Receiver Set

Radian Weapons Model 1 10" Upper Receiver and Handguard Set, Flat Dark Earth

AERO PRECISION M5 308 Win Assembled Upper Receiver | OD Green

AERO PRECISION M5 308 Assembled Upper Receiver | Kodiak Brown Anodized

AERO PRECISION M5 .308 Stripped Upper Receiver - Anodized Black

Wraithworks Billet Slick Side AR-15 Upper Receiver - Black | No Forward Assist or Brass Deflector

WILSON COMBAT Forged Lower/Upper Matched Receiver Set (TR-LOWUPP-CTG-ATB)

AERO PRECISION M4E1 Complete AR15 Lower Receiver w/ A2 Grip & M4 Stock - Black