The Underworld Arms Aug M-Lok handguard is 5.5" long and is machined from T6-6061 with a black anodized finish and includes a top rail for extending the iron sight radius. The handguard includes a black oxide 304 SS locking nut, a black oxide 304 SS mounting nut, and a black polymer centering plug for use during install.
When installed the quick change barrel feature is functional and gas adjustment is accessible, the original grip can be left on or removed.
The UA Aug M-Lok handguard mounts to the barrel using our proprietary hybrid method that takes inspiration from an AR15 style barrel nut and the Aug's locking flash hider nut.
This 5.5" Aug handguard is designed for standard 16" barrels and will fit on A1, A2 and A3 receivers, and we are currently machining a run of longer handguards made for the classic 20" barrels.
To install the handguard remove your muzzle device, apply rocksett or a similar threadlocker to your bayonet lug threads. Thread on the square locking nut with the unthreaded ID facing the receiver, thread on the wing shaped mounting nut with the wing side facing the receiver. Orient the flats of the mounting nut at the 12 o-clock and 6 o-clock and tighten the nuts together. Slide your handguard on and attach it to the mounting nut with the included 8-32 screws. Be sure to use your choice of thread locker on the screws so they do not back out. Test the barrel's quick detach function, if the handguard rail engages the receiver then unthread your mounting nut a half rotation.
Rocksett has a 24 hour setup time, you do not need to rush the process there is plenty of time to line everything up perfectly.
Included in the box is a black polymer centering plug that lines up the handguard with the barrel, this does not have to be used during installation but it does make squaring the handguard with the barrel easier and faster. If you chose to use the delrin plug for your installation remember to remove it after you are done.
Inside Diameter- 1.52"