Stern Defense, Llc Ar-15 Sd Mod 4 9mm Upper Receiver 4in M-Lok Complete

The Stern Defense SD Mod 4 9mm Upper Receiver is a complete, ready to go, upper receiver solution for those looking to spend less time building and more time shooting. The 4 inch, 1-10 twist, Melonited barrel, is free float in a 4in M-LOK handguard attached to a 7075-T6 forged aluminum receiver. On the end of the barrel mounted on the 1/2-36 threads is a 1.75" long, 1.2" diameter blast can designed to direct the short barreled blast away from the shooter. 4in barrel 4in M-LOK Free Float handguard Complete assembly with 9mm bolt and charging handle 1/2-36 muzzle thread pitch 1.75" long by 1.2" diameter blast can muzzl Mfg: Stern Defense, Llc