High-quality carbon steel, 7.62x39mm chambered barrel with 1:9.5" twist rate features chrome-lined chamber and bore for maximum service life. Matte black/dark gray Parkerized finish provides corrosion- and wear-resistance. Comes with 14x1mm left-hand muzzle threads. Fits 23mm trunnions. Requires gas port drilling and headspacing set by a knowledgeable gunsmith. 1970 barrel fits M70 Yugoslavian receivers with fixed or underfolder stock; no side cuts. 1975 barrel has the side cuts and fits receivers of American, Romanian, Polish, Maadi, and clones with fixed or underfolder stocks.