
Availability: In Stock
Current Stock: Out of stock
The CMMG Mkgs Complete Bolt Carrier Group Repair Kit for .40 S&W gives you everything you need to service or rebuild your rifle's BCG without waiting for a gunsmith. Whether you're doing routine maintenance, replacing worn components, or building a rifle from the ground up, this kit supplies all the essential parts in one package. It's built for shooters who take ownership of their gear and understand that quality upkeep extends the life and reliability of your rifle.
Each .40 S&W kit includes a complete bolt assembly paired with a carrier key system, firing control components, and springs—the critical pieces that see the most wear and stress during firing cycles. CMMG engineered this kit to simplify the rebuild process, so you're not hunting down parts individually or worrying whether incompatible components will work together. All parts are compatible and ready to go.
This is ideal for shooters who run .40 S&W platforms and want a genuine OEM repair solution on the shelf, ready when you need it. It's also practical for builders and folks who maintain multiple rifles and need spare parts on hand. No guesswork, no substitutes—just the real parts your BCG demands.
| Caliber | .40 S&W |
| Brand | CMMG |
| Component Type | Bolt Carrier Group Repair Kit |
| Included Parts | Bolt, Firing Pin, Firing Pin Retainer Pin, Key (RDB), Key Screws (x2), Bolt Cam Pin, Extractor, Ejector, Ejector Spring, Bolt Spring (RDB) |
This kit is specifically built for .40 S&W rifles. It's important to choose the correct caliber—CMMG also offers this kit in 9mm, so make sure you're ordering the .40 S&W version for your platform.
Yes. This complete kit includes all the major components needed to service or rebuild a bolt carrier group: the bolt, firing pin assembly, extractor, ejector, springs, pins, and the carrier key with screws. It's designed to give you a full set of parts in one purchase.
The kit contains: bolt, firing pin, firing pin retainer pin, RDB-style key with two key screws, bolt cam pin, extractor, ejector, ejector spring, and RDB bolt spring. These are all the essential components for a complete bolt carrier group assembly or repair.
Yes, this kit works well for builders and shooters assembling or upgrading .40 S&W rifles. Having a complete set of OEM parts ensures compatibility and simplifies the build process.

SKU: 167529163 • Weight: 0.21oz





Availability: In Stock
Current Stock: Out of stock
The CMMG Mkgs Complete Bolt Carrier Group Repair Kit for .40 S&W gives you everything you need to service or rebuild your rifle's BCG without waiting for a gunsmith. Whether you're doing routine maintenance, replacing worn components, or building a rifle from the ground up, this kit supplies all the essential parts in one package. It's built for shooters who take ownership of their gear and understand that quality upkeep extends the life and reliability of your rifle.
Each .40 S&W kit includes a complete bolt assembly paired with a carrier key system, firing control components, and springs—the critical pieces that see the most wear and stress during firing cycles. CMMG engineered this kit to simplify the rebuild process, so you're not hunting down parts individually or worrying whether incompatible components will work together. All parts are compatible and ready to go.
This is ideal for shooters who run .40 S&W platforms and want a genuine OEM repair solution on the shelf, ready when you need it. It's also practical for builders and folks who maintain multiple rifles and need spare parts on hand. No guesswork, no substitutes—just the real parts your BCG demands.
| Caliber | .40 S&W |
| Brand | CMMG |
| Component Type | Bolt Carrier Group Repair Kit |
| Included Parts | Bolt, Firing Pin, Firing Pin Retainer Pin, Key (RDB), Key Screws (x2), Bolt Cam Pin, Extractor, Ejector, Ejector Spring, Bolt Spring (RDB) |
This kit is specifically built for .40 S&W rifles. It's important to choose the correct caliber—CMMG also offers this kit in 9mm, so make sure you're ordering the .40 S&W version for your platform.
Yes. This complete kit includes all the major components needed to service or rebuild a bolt carrier group: the bolt, firing pin assembly, extractor, ejector, springs, pins, and the carrier key with screws. It's designed to give you a full set of parts in one purchase.
The kit contains: bolt, firing pin, firing pin retainer pin, RDB-style key with two key screws, bolt cam pin, extractor, ejector, ejector spring, and RDB bolt spring. These are all the essential components for a complete bolt carrier group assembly or repair.
Yes, this kit works well for builders and shooters assembling or upgrading .40 S&W rifles. Having a complete set of OEM parts ensures compatibility and simplifies the build process.
SKU: 167529163 • Weight: 0.21oz
