CMMG AR-15 Bolt Catch Kit - Black - This CMMG Bolt Catch kit is fully compatible with any mil-spec AR-15. CMMG factory parts are a great choice for any new AR build, or for fixing up an older rifle that needs a little TLC. Bolt catch kit for AR15 and CMMG Mk4, MkGs, MkG, Mk17, and Mk57 lower receivers. Made in the USA ; Includes: Bolt Catch; Bolt Catch Plunger; Bolt Catch Spring; Bolt Catch Roll Pin; - At Sportsman's Warehouse, we live for the thrill of the great outdoors. Whether you're hunting, fishing, camping, backpacking, or shooting, having the right gear is key to making every moment unforgettable. That's why we bring you only the highest quality, trusted brands-because your outdoor experiences deserve the best. From expert advice to quality gear and community events, Sportsman's Warehouse is more than a store-we're your partner on every journey. Come explore with us and experience the difference passion makes.