Shop › COLT M4 UPPER BLK COLT M4 UPPER BLK $179.99 sold out Colt's Manufacturing Upper, 223REM/556NATO, Black Finish, Dust Cover, Forward Assist, M4 Feed Ramps SP63528 Sold Out Added! Colt's Manufacturing Upper, 223REM/556NATO, Black Finish, Dust Cover, Forward Assist, M4 Feed Ramps SP63528