ROCK RIVER ARMS 300BLK 10.5" UPPER HALF W/MID MLO

TacFire AR-15 .300 Blackout Unassembled Upper Receiver Kit - 5"

CMMG 30BC40AMB Resolute MK4 300 Blackout 16.10", Midnight Bronze, M-LOK Free-Float Handguard for AR-Platform (No BCG or Charging Handle)

ALEXANDER AR15 STANDARD UPPER - 300AAC 16" BLACK

AERO PRECISION M5 308 Win Assembled Upper Receiver | OD Green

Patriot Ordnance Factory Wonder 13.75 300 Blue Titanium Mid Length Upper

AMERICAN TACTICAL IMPORTS AR15 Milsport RIA Alum Rec 300Blk 16" Rgr Stk 30rd

CMMG Dissent 6.50" Upper .300 AAC Blackout with 1:7 Twist Rate and M-LOK Rail - Pistol-Length with Charging Handle - Armor Black - 30B0E67AB