USGI barrel nut wrench
3/32” Allen Wrench
1. Clean and inspect upper receiver, barrel and barrel nut.
2. Place receiver in proper vise block.
3. Coat threads with grease or anti seize compound.
4. Install barrel into receiver. Be sure to align indexing pin with slot in upper receiver.
5. Slip barrel nut over barrel and thread onto upper receiver hand tight.
6. Using a standard USGI barrel nut wrench, torque nut to 30-50
ft-lbs. Check alignment of gas tube hole in upper receiver. You
may need to loosen and tighten nut once or twice to get proper
alignment and torque.
7. Install gas tube and gas block, per proper instructions.
8. Slip handguard over barrel and gas block.
9. Align screw holes in handguard with holes in barrel nut.
10. Start all screws before tightening any of them. We recommend blue thread locking compound.
11. Make sure everything is aligned properly and installed correctly.
12. Tighten all screws.
13. Enjoy your new, state of the art handguard.