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 ½-36 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
- ½-36 muzzle thread pitch
- 1.75” long by 1.2” diameter blast can muzzle device
- SD BU9 9mm Bolt
- Cartridge: 9mm Nato
Included in the upper receiver is charging handle and the Stern Defense 9mm Bolt which is compatible with both Glock®and Colt SMG magazines, has a Melonite finish, and is works in conjunction with the Law Tactical Folding Adapter. The Stern Defense SD Mod 4 9mm Upper Receiver is made in the U.S.A.
SD MOD 4 9mm Upper Receiver 4in M-LOK Complete Black