2pcs Shim for .223 / 5.56 Free Float Barrel Nuts

2pcs Timing Shims for .223 / 5.56 Free Float Barrel Nuts

AR15 .223/5.56 Barrel Nut Shim. Barrel Nut Shims are a great compliment to any .223 Free Float Quad Rail . If your forend doesn’t have the ability to “time” the position of the forend in relationship to the upper receiver the shim will give you this capability. This 0.5mm stainless steel shim fit between the barrel nut and upper receiver to allow the user to adjust the relationship between the gun and the forend/handguard features like swivel studs, vent openings, and picatinny rails. Fits .223, 5.56, 7.62x39, and .300 AAC Blackout upper recievers. (Will NOT fit AR-10 rifles.)