Luth-ar LRPK-1 Lower Receiver Parts Kit AR-15 .223 Rem/5.56 NATO Black

Building an AR-15 from a stripped lower receiver doesn't have to mean hunting down a dozen different suppliers for scattered parts. The Luth-AR LRPK-1 Lower Receiver Parts Kit AR-15 brings together all the mil-spec fire control components and hardware you need to complete a lower receiver in one order. Whether you're assembling your first AR or your tenth, this kit eliminates the frustration of discovering mid-build that you're missing a spring, pin, or detent—something that happens to every builder at least once.

The LRPK-1 includes the complete fire control group (trigger, hammer, disconnector, and associated springs), all takedown and pivot pins with detents, magazine catch assembly, bolt catch, safety selector, trigger guard, buffer retainer hardware, and a standard A2-type black plastic pistol grip to get you started. You get everything except the stripped lower itself, buffer tube, buffer, and stock—parts you'll source based on your build's specific needs. This is mil-spec across the board, meaning reliable, proven performance and full compatibility with standard AR-15 platforms chambered in .223 Remington or 5.56 NATO.

Keep in mind this kit requires assembly; the parts arrive uninstalled. If you've built an AR before, installation is straightforward. New builders should study an assembly guide or video before starting. The included A2 grip is functional plastic, adequate for shooting while you decide if you want an aftermarket upgrade down the road.

Key Features

• Complete mil-spec fire control group (trigger, hammer, disconnector)
• All pins, springs, and detents for lower assembly
• Includes bolt catch, safety selector, trigger guard, and magazine catch assembly
• Buffer retainer and retainer spring included
• A2-style black plastic pistol grip with hardware
• One-kit ordering eliminates part-hunting
• Compatible with .223 Rem/5.56 NATO lower receivers

Specifications

Frequently Asked Questions

What's included in the Luth-AR LRPK-1 kit?

The kit contains the complete fire control group (trigger, hammer, disconnector), safety selector with detent, trigger guard, bolt catch, magazine catch assembly, all takedown and pivot pins with detents and springs, buffer retainer with spring, and a black A2-type plastic pistol grip with bolt and lock washer. Everything is mil-spec.

Do I need to assemble this kit, or is it drop-in?

This kit requires assembly. The parts arrive uninstalled and must be installed into your stripped lower receiver. If you're new to AR builds, consult an assembly guide or instructional video before starting.

What caliber and platform does this kit fit?

The LRPK-1 is designed for AR-15 platform lower receivers chambered in .223 Remington or 5.56 NATO.

What do I still need to complete my AR-15?

You'll need a stripped lower receiver, upper receiver assembly, buffer tube, buffer, and stock. This kit handles the lower receiver fire control and assembly hardware.