GUNBUILDER'S LOWER PARTS KIT FOR AR-15 LOWER Reviews & Ratings

CMMG® Lower Parts Gunbuilder's Kits contain the needed parts to complete an AR-15 lower receiver. These kits come less the trigger, grip and trigger guard.

INCLUDES:

Takedown pin
Receiver pivot pin
Takedown pin detent (2)
Takedown pin detent spring (2)
Hammer and trigger pin (2)
Safety selector
Selector detent
Magazine catch
Magazine catch spring
Magazine release button
bolt catch
Bolt catch plunger
Bolt catch spring
Bolt catch spring pin
Buffer retainer
Buffer retainer spring

See all of our AR15s and AR15 parts here.

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2 Stars

Reviews Summary

Customers are highly satisfied with the GUNBUILDER'S LOWER PARTS KIT, praising its quality, fit, and value for money. Many enjoy the convenience of labeled parts, making assembly easier, and appreciate the ability to customize their builds. A few wished for more options like an ambidextrous model, but overall feedback is overwhelmingly positive.

What Reviewers Are Saying

Product Quality

92%

Reviewers frequently highlight the superior quality of the parts, noting excellent machining and finish. Many assert that every component functions flawlessly, contributing to a reliable build experience.

Ease of Assembly

75%

Numerous customers mention the simplicity of assembling the kit, especially praising the labeled packaging that aids even beginners. Many highlight their success in building ARs using this kit without any issues.

Customization Options

42%

Several reviews express satisfaction with the kit's flexibility, particularly the absence of standard parts like a trigger and grip, allowing users to choose their own. Reviewers appreciate this approach as it saves money and enhances personalized builds.

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AR-15 parts

Worked as advertised.

by William M. on March 30, 2026

Verified Purchase

Was this review helpful? 1

Worked great

All parts there. All parts fit. All parts function. Worked great.