F1 Firearms Threaded 223 Wylde Standard Fluted Rifle Barrel - 16in - Black Nitride - Complete your rifle with this F-1 Firearms standard fluted black nitride barrel chambered in 223 Wylde. The .223 Wylde chambered barrel is safe to shoot both .223 Remington or 5.56 NATO ammunition safely without sacrificing performance. Standard fluted 16" barrel Chambered in 223 Wylde 5R rifling - button pulled 1:7 twist Mid-length gas system Dimpled gas block mount .750-inch gas block diameter 1/2"x28 threads 11-degree cone Black nitride finish