Shop › RADICAL UPPR 556 16" 1-7 MLOK BLK RADICAL UPPR 556 16" 1-7 MLOK BLK $433.97 Radical Firearms Complete Upper Assembly, 223 Rem/556NATO, 16" Barrel, 1:7 Twist, Black, MLOK Handguard, A2 Flash Hider RF00325 Quantity: Add To Cart Added! Radical Firearms Complete Upper Assembly, 223 Rem/556NATO, 16" Barrel, 1:7 Twist, Black, MLOK Handguard, A2 Flash Hider RF00325