CMMG MK9 Bolt Catch

This CMMG Bolt Catch is a replacement bolt catch built for CMMG’s MK9 (9mm AR-pattern) platform.

Key Specifications

• Built for CMMG MK9 9mm AR-pattern rifles/pistols.
• Functions as the bolt catch that locks the bolt open on an empty magazine.
• Sold individually as a single replacement part, not bundled as part of a multi-piece kit.
• A commonly stocked spare/replacement part for armorers, gunsmiths, and home builders performing lower parts kit (LPK) installation or repair.
• Classified as a firearm part/accessory, not a regulated firearm itself — no FFL transfer required to purchase.

Frequently Asked Questions

What platform does this bolt catch fit? This bolt catch is built for CMMG’s MK9 9mm AR-pattern platform.

Does this fit a standard 5.56 AR-15? This part is built for CMMG’s MK9 9mm platform; check compatibility before installing on a different caliber AR-15 variant.

Buy the CMMG MK9 Bolt Catch

Order the CMMG MK9 Bolt Catch from a Lubbock, TX gun shop. Browse more CMMG parts in our Small AR15 Parts category.