CMMG MK9 Bolt Rehab Kit - Complete Maintenance Solution for 9mm AR

The CMMG MK9 Bolt Rehab Kit is a complete maintenance solution purpose-built for shooters running 9mm AR platforms. Whether you're deep into competition, dedicated to range time, or pushing your 9mm AR hard in the field, bolt wear and carbon buildup are inevitable—and this kit gives you everything needed to refresh the critical components that make reliable fire. CMMG engineered these parts to exact tolerances for their MK9 system, so you're getting OEM-spec replacements that restore function without guesswork or compatibility headaches.

Bolt maintenance often gets overlooked until reliability suffers. The MK9 Bolt Rehab Kit addresses the wear points that matter: the firing pin and its spring handle ignition consistency, the extractor and its pin manage reliable case ejection, and the firing pin retainer keeps everything locked in place. If you've noticed light primer strikes, inconsistent extraction, or just want to stay ahead of wear during a rebuild, having these components on hand means you can service your bolt in minutes rather than waiting for a gunsmith or sourcing parts piecemeal.

This kit is ideal for 9mm AR owners who take maintenance seriously—whether that's competitive shooters who run high round counts, hunters who demand reliability in the field, or builders who prefer to keep a spare complete bolt assembly. CMMG's parts are machined to consistent standards, so swapping them in restores factory-spec performance.

What's Included

• MK9 Firing Pin
• MK9 Firing Pin Spring
• Firing Pin Retainer
• MK9 Extractor
• MK9 Extractor Pin

Frequently Asked Questions

Is the CMMG MK9 Bolt Rehab Kit compatible with all 9mm ARs?

This kit is engineered for CMMG's MK9 platform specifically. Verify your rifle's bolt design matches MK9 specs before ordering to ensure proper fit and function.

Can I use this kit to rebuild an existing bolt or do I need a new one?

The kit contains the internal and wear components that fit within a standard MK9 bolt carrier. You can use it to refresh an existing bolt that's showing wear, or assemble these parts into a complete assembly as part of a build or maintenance cycle.

What does this kit address in terms of bolt maintenance?

The firing pin, spring, and retainer manage reliable ignition; the extractor and pin ensure consistent case ejection. Together, they cover the main wear points in the bolt assembly and are the typical parts you'd replace during a rehab or preventive maintenance cycle on a high-round-count gun.