AR15 .223 Barrel Nut Washer / Free Float Quad Rail Barrel Nut Shim 0.5mm- Stainless Steel Black

AR15 .223 Barrel Nut Washer / Free Float Quad Rail Barrel Nut Shim. Barrel Nut Shims are a great compliment to any .223 Free Float Quad Rail . If your forearm doesn’t have the ability to “time” the position of the forearm in relationship to the gun, or 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 forearm features like swivel studs, vent openings, and picatinny rails. Fits .223, 5.56, 7.62×39, and .300 AAC Blackout upper recievers. (Will NOT fit AR-10 rifles.)