The Caldwell M&P Essentials Parts Kit (part no. 1078425) rounds up the small, easy-to-lose pieces that hold an AR-platform fire control group and buffer system together, so a build or repair doesn’t stall out over one missing detent spring. Caldwell packages every commonly broken or misplaced small part into a single kit instead of making you source each one individually. Whether you’re finishing a first build, restocking a bench, or repairing a lower that’s shedding small parts on a range mat, this kit covers the pieces that are easy to lose and surprisingly hard to find one at a time.

Key Specifications

• Includes the bolt catch group: plunger, spring, and roll pin.
• Includes the buffer retainer and its spring.
• Includes the disconnector spring for the fire control group.
• Includes the hammer spring and trigger spring.
• Includes the hammer pin and trigger pin.
• Includes the pivot pin detent and detent spring.
• Includes the takedown pin detent and detent spring.
• Includes the selector detent and detent spring.
• Includes the trigger guard roll pin and magazine catch spring.

Frequently Asked Questions

What’s included in this kit? Eighteen small parts covering the bolt catch, buffer retainer, fire control springs and pins, detents, and the magazine catch spring.

Is this kit sized for a standard AR-platform lower? Yes, it covers the small parts used across standard AR-platform builds.

Buy the Caldwell M&P Essentials AR-Platform Parts Kit

It’s never the big parts that stall a build, it’s the detent spring that pings off into the grass, and this kit restocks every one of those small pieces in a single order. Order it from our Lubbock, Texas gun shop and it ships fast to your door, along with more AR-15 lower parts.