For the part of the western twist this rifle is chambered in 5.56 NATO which opens up the possibilities for shooting at longer ranges. some other nice ergonomic features that this rifle has is the addition of an adjustable gas block a bolt hold open safety. And for that classic look and feel this rifle comes with nice walnut furniture. So get a rifle that gives that classic AK-47 Feel with that little bit of Western twist with the ZPAP M90 from Zastava. Caliber: 5.56×45 NATO (Also Accepts .223 Remington) Semi Automatic Rifle Long Stroke Gas Piston System Adjustable Gas Block Hollow Piston Head 30 Rounds 18.25″ Cold Hammer Forged Chrome Lined Barrel 1:7 Twist 14×1 LH Threaded Muzzle 1.5 mm Bulged Trunnion Receiver Standard AKM Sights Walnut Wood Furniture Accepts Yugo Style Side Mounts Bolt Hold Open Safety Length of Pull 16.3″ Overall Length 39″ Weight: 8.5 lbs Color: Black Cerakote Finish