Radical Firearms RF-15, Semi-automatic, AR Pistol, 300 Blackout, 8.5 HBAR Threaded Barrel, Anodized Finish, Black, Pistol Length Gas System, A2 Flash Hider, MFT Engage V2 Grip, 7 M-LOK Handguard, 30 Rounds, 1 Magazine RF00146 The Radical Firearms 8.5" HBAR 300 BLK AR Pistol uses MIL-STD Upper and lower receivers along with their 7" RPR free float rail system for increased accuracy, keeping your hands cool, and giving you plenty of room for accessories.