$525.00The MAX-11Sk upper receiver can be used with the M-11/9 submachine gun. NFA rules apply to the use of this upper with a semi-auto pistol upper receiver, due to the K-Grip on the front. This upper receiver is also a great upper to use with your Tungsten Slow Fire Bolt (CF-W). Features a full length accessory rail on top and integrated K-Grip on bottom.. Made from 6061 aluminum and finished in black, hard coat anodize. 5-3/4 inch length barrel threaded 1/2-28 at the muzzle with Bull Nose Thread Protector installed. Cocking piece is non-reciprocating. Does not include a bolt assembly.