VARMINT RIFLE BT-3 WITH 20-INCH STAINLESS STEEL BULL BARREL CALIBER:.308 / 7.62X51MM NATO CHAMBER. LOWER RECEIVER:RRA BT-3 BILLET LOWER. UPPER RECEIVER:RRA BT-3 BILLET A4 UPPER. BARREL:20-INCH STAINLESS STEEL BULL, 1:10 TWIST, CRYOGENICALLY TREATED. GAS BLOCK:LOW PROFILE GAS BLOCK, RIFLE LENGTH GAS SYSTEM. TRIGGER:RRA TWO STAGE TRIGGER. BUTTSTOCK:RRA 6-POSITION NSP-2 CAR STOCK. PISTOL GRIP:HOGUE RUBBER GRIP. HANDGUARD:RRA LIGHTWEIGHT FREE FLOAT RAIL, 17 INCH EXTENDED, M-LOK COMPATIBLE