Geissele Automatics Super Duty Assembled AR-15 Upper Receiver

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

Battle Arms Development WH556-URS-ODG Workhorse Upper Receiver Aluminum OD Green Anodized Receiver for AR15/M4

Guntec USA AR15 Upper Receiver Compatible With AR-15 Accessories

AERO PRECISION AR15 5.56 NATO / 223 Rem 20" Complete Upper Receiver w/ Carry Handle | Black

American Tactical Milsport AR-15 Lower Receiver with A2 Stock/Grip - Complete Lower

TacFire AR-15 .223 / 5.56 Unassembled Upper Receiver Kit - 10"

Timber Creek Outdoors TCO Enforcer Upper Parts Kit for AR-15, Blue - E UPK B