WHAT IS A BATTLE RIFLE ? .. A BATTLE RIFLE IS PISTON DRIVEN RIFLE .. PISTON DRIVEN RIFLES BOLT CARRIER GROUP DOESN'T GET HOT , HOT GASSES DON'T GUM UP THE BOLT CARRIER , CYCLES BULLETS WITHOUT FAIL , CHAMBER STAY COOL BECAUSE OF A HEAT SINK BARREL NUT .. A BATTLE RIFLE CAN SHOOT => ALL DAY LONG WITHOUT FAIL <= .. YES IT IS MORE EXPENSIVE THAN A DIRECT IMPINGMENT RIFLE WHERE HOT GASSES INSTEAD OF A PISTON BLOW THE BOLT CARRIER BACK LEAVING BURNT HOT STICKY POWDER RESIDUE IN ON THE BOLT ..