Spear Manufacturing Steel Jam Locking Nut AR15 5.56 AR-15
Locking Nuts have the effect that two nuts turned opposite directions on a bolt do. They tighten against each other and lock. A Locking Nut is placed on the threaded barrel first, followed by the muzzle device. While the muzzle device is tightened down, the Locking Nut is held in place until the muzzle device reaches it and then turned in the opposite direction to lock it. These can be used in place of either Crush Washers or Shims if there’s enough room (based on the muzzle device). This jam nut is .19" wide and fits most standard AR barrels with .60" of thread area.