CMC AR-15 Lower Parts Kit

Description

CMC AR-15 Lower Parts Kit

Because bargain bin kits are notorious for soft roll pins and undersized springs, a CMC AR-15 lower parts kit is the fastest way to finish out a lower build without the guesswork.

This CMC AR-15 lower parts kit supplies every mil-spec component needed to complete a lower build except the fire control group and pistol grip, which CMC leaves out on purpose so builders can pair the kit with whatever trigger and grip they actually want. Because CMC Triggers built its reputation on the original drop-in precision trigger for the AR-15/10 platform, the company applies that same manufacturing standard to its lower parts kits. As a result, every roll pin, spring, and detent in this kit is held to mil-spec tolerances, which matters the moment an undersized bolt catch spring or a soft takedown pin turns an easy build into a return trip to the parts bin.

Specifically, the kit covers the bolt catch assembly, magazine release system, buffer retainer components, safety selector and detents, trigger guard, and the full takedown pin set — seventeen pieces in total. Since none of these components are caliber-specific, the kit drops into any standard mil-spec AR-15 lower, regardless of chambering. Add a fire control group and grip of your choosing, and the lower is ready to mate up to your upper.

Key Features — CMC AR-15 Lower Parts

• Bolt catch assembly with bolt catch, plunger, spring, and roll pin
• Magazine release system: mag catch, release button, and spring
• Buffer retainer and buffer retainer spring
• Safety selector with detent and detent spring
• Trigger guard and trigger guard roll pin
• Full takedown pin set: two detents, two detent springs, two pins
• Every part manufactured to meet or exceed mil-spec tolerances
• Fire control group and pistol grip intentionally excluded so you can select your own

 

Why This Product Stands Out

CMC Triggers didn’t start as a parts kit company, and that background shows up here. Because the same shop that engineered the original drop-in AR trigger also machines and finishes these lower parts, the fit and finish is noticeably tighter than what typically ships in a generic bargain kit. In particular, builders who have dealt with a bent bolt catch roll pin or a magazine release spring that loses tension after a few hundred rounds understand why that consistency is worth paying attention to.

Since most builders already have firm opinions about their trigger and grip, this kit respects that instead of forcing a choice on them. Rather than bundling in a fire control group you’ll just replace anyway, CMC keeps the kit focused on the parts almost nobody wants to shop for individually, so you can spend your budget on the components that actually change how the rifle shoots.

Ideal Use Cases

• New AR-15 lower build from a stripped receiver
• Replacing worn or damaged OEM lower parts
• Keeping a spare kit on hand for field repairs or troubleshooting
• Pairing with an upgraded trigger and grip for a fully custom lower

 

Compatibility

Because this kit contains no caliber-specific parts, it fits any standard mil-spec AR-15 lower receiver. Therefore, a separately purchased fire control group and pistol grip are required to complete the build.

Technical Specifications

 

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Manufacturer: CMC Triggers | Model: 81500 | Type: Lower Parts Kit (No FCG/Grip) | UPC: 859464006062 | SKU: 81500