Shop › FZ M16/M4 BOLT CARRIER GROUP FZ M16/M4 BOLT CARRIER GROUP $189.99 FailZero Bolt Carrier Group With Hammer, Completely Assembled, EXO Coated, Fits M16/4, Nickel Finish FZ-M164-01-SAH Quantity: Add To Cart Added! FailZero Bolt Carrier Group With Hammer, Completely Assembled, EXO Coated, Fits M16/4, Nickel Finish FZ-M164-01-SAH