Most 5.56x45, .223, and .223 Wylde AR15 barrels are threaded 1/2x28 but not all. It is a safe bet this one is as well though.
Most 5.56x45, .223, and .223 Wylde AR15 barrels are threaded 1/2x28 but not all. It is a safe bet this one is as well though.