Shop › CMMG LPK 556 WITHOUT GRIP/FIRE CONTR CMMG LPK 556 WITHOUT GRIP/FIRE CONTR $39.95 CMMG Lower Receiver Parts Kit, 556NATO, Without Grip/Fire Control Group 55CA601 Quantity: Add To Cart Added! CMMG Lower Receiver Parts Kit, 556NATO, Without Grip/Fire Control Group 55CA601