YHM BLACK DIAMOND SPECTER XL, UPPER RECEIVER GROUP 6.8MM YHM-7820-68

LWRC SIX8 PSD Complete Upper Receiver 6.8 REM SPC 8.5" - Black

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

AERO PRECISION M5 20" .308 CMV Complete Upper Receiver w/ ATLAS S-ONE M-Lok 15" Handguard

Wilson Combat Silent Bandit 6.8mm .277" Black Nitride 5/8"x24

FIERCE FIREARMS MTN REAPER 308WIN BRONZE 18" #

AERO PRECISION M4E1-T 5.56 NATO 11.5" Complete Upper Receiver | Black

Sons of Liberty Gun Works SOLGW 14.50" Upper 5.56x45mm M-LOK Rail - Tactical Excellence - M4L89BSCHF14.5