This semi automatic rifle is chambered in 5.56×45, features a 18.5″ chrome lined barrel with a 1:7″ twist rate and is threaded 14x1LH. The trunnion is buldged with a 1.5MM receiver. There are 3 adjustable gas settings so you can quickly dial in the rifle to your chosen ammo and muzzle device. Complete with a beautiful Serbian Red wood stock set this rifle is quite the looker. Comes with 1-30 round Zastava Arms magazine.