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. Mfg: Green Mountain SPECS: 4140 carbon steel, chrome lined, black oxide exterior finish. 16-3/8" (41.5cm) long. 14-1mm LH muzzle thread. 1:9.5" twist. Fits 23mm trunnions. 1970 – 21.5 oz. (610g) wt. 1975 – 19.4 oz. (550g) wt.