- Product Code: 55CA601
CMMG Lower Parts AR15 Gunbuilder's Kit – a spare parts kit for assembling and maintaining an AR-15 lower receiver, which includes most of the necessary small parts but intentionally leaves out commonly replaced parts. The package does not include a Trigger Guard, Fire Control Group, or Pistol Grip, allowing you to choose the components you want for your upgrade parts.
This kit gathers the critical small parts for an AR-15 lower, such as the bolt catch assembly, safety assembly, magazine catch assembly, pivot and takedown pins with their detents and springs, as well as the buffer retainer and spring. The parts are sized to be AR-15 compatible, making assembly smooth and ensuring a reliable fit. Builders benefit from the fact that the package is specifically selected for essential small parts.
What makes this set special is that it is assembled with building in mind: it includes just the springs, pins, and detents that are often missing or wear out in use. At the same time, it leaves the buyer the freedom to separately acquire the trigger mechanism, trigger guard solution, and pistol grip of their choice. This enables flexible customization and keeps maintenance and building well-planned.
CMMG Lower Parts AR15 Gunbuilder's Kit - Features:
- Description: spare parts kit for assembling an AR-15 lower receiver
- Compatibility: AR-15 lower receiver
- Manufacturer: CMMG
- Contents: Bolt catch and roll pin
- Contents: Bolt catch plunger and spring
- Contents: Trigger and hammer retaining pins
- Contents: Safety (selector), detent, and spring
- Contents: Magazine catch, magazine catch spring, and release button
- Contents: Pivot pin and takedown pin, their detents and springs
- Contents: Buffer retainer and spring
- Does not include: Trigger Guard
- Does not include: Fire Control Group
- Does not include: Pistol Grip
- Purpose: assembly, maintenance, and spare parts use for a lower receiver
Summary: CMMG's builder's kit is a well-thought-out set for building an AR-15 lower when you want to use your choice of trigger, grip, and trigger guard solutions. It gathers the critical small parts together and makes assembly straightforward, offering a clear and cost-effective way to finish or maintain a lower receiver.
Recommended use: for builders and maintenance tasks when the essential small parts for an AR-15 lower receiver are needed, and you want to choose the FCG, Trigger Guard, and Pistol Grip separately.
Product text updated on 9.3.2026.
