The Radical Firearms 16" heavy profile 7.62x39 AR rifle uses MIL-STD Upper and lower receivers along with our 15" RPR free float rail system for increased accuracy keeping your hands cool and giving you plenty of room for accessories. Regardless if it's your first or fiftieth a Radical Firearms AR rifle will not disappoint! Barrel Length: 16" Barrel Material: 4150 Chrome Moly Vanadium Barrel Finish: Melonite Barrel Profile: Heavy Profile Barrel Thread Pitch: 5/8x24 Chamber: 7.62x39 Twist Rate: 1:10 Barrel Extension: M4 Feed Ramps Gas System: Carbine Length Gas Block Type: .750 Low Profile Gas Block Muzzle Device: A2 Flash Hider Upper Receiver Material: Forged 7075 T6 Upper Receiver Style: M4 MIL-STD Upper Receiver Finish: Type III Anodizing Forward Assist: MIL-STD Dust Cover: MIL-STD Handguard Type: Free Float Handguard Style: M-Lok Thin Rail Handguard Length: 15" Charging Handle: MIL-STD Lower Receiver: Forged 7075 T6 Lower Receiver Finish: Type III Anodizing Fire Control Group: MIL-STD Grip: MFT EPG16V2 Grip Buffer Tube: Carbine MIL-STD Stock Adjustment: 6 Postion Stock: MFT Minimalist Magazine: 7.62x39 10 round