The Arsenal SLR-107R rifle features a 16.25-inch (415 mm) chrome-lined, cold hammer-forged barrel. It is a 7.62x39mm caliber stamped receiver rifle with a 14x1mm left-hand threaded muzzle and a removable muzzle nut. The overall length is 36.88 inches. Barrel Specifications: Length: 16.25 inches. Type: Chrome-lined, Cold Hammer Forged Thread Pitch: 14x1mm LH Twist Rate: 1:9.44 (1 in 240 mm)Grooves: 4 The SLR-107R is known for its Bulgarian-made components, including the barrel, which provides high durability. It is designed for standard 7.62x39mm AK-47 accessories and has a gas block with a bayonet lug.