Luth-AR 308 Lower Receiver Parts Builder Kit
$44.17
$46.99
(You save
$2.82
)
- Firearm Group:
- Lower
- Caliber-Gauge:
- 308 Caliber
- Finish-Color:
- Black
Building an AR-10 from a stripped lower receiver means sourcing all the small parts that make the gun function—and doing it right matters. The Luth-AR .308 Lower Receiver Parts Builder Kit is a purpose-built collection of components designed specifically for the .308 AR platform, giving you the core parts needed to assemble a functional lower without buying everything piecemeal. If you're a serious builder who wants mil-spec quality without the guesswork, this kit cuts through the noise.
Luth-AR manufactures these parts in-house using investment casting and precision machining to mil-spec drawings, materials, and heat-treat standards—no MIM (metal injection molded) shortcuts here. Springs are a mix of 17-4 stainless steel and certified mil-spec steel wire, chosen for reliability and longevity. The builder kit includes the trigger, hammer, selector/safety, bolt catch assembly, magazine catch, takedown and detent springs, pivot pins, and all the pins and fasteners required to bring your lower to life. You get quality American-made parts that'll hold up to hard use.
This is the builder option, meaning you're assembling these components yourself—a straightforward process if you've done it before or have a guide handy. It's ideal for AR-10 builders who want to control every aspect of their rifle's lower assembly and trust the parts they're putting in. Whether you're building for long-range hunting, precision shooting, or a custom build, starting with mil-spec components from a maker who actually mills their own parts gives you a solid foundation.
Key Features
- Investment-cast and machined components built to mil-spec drawings and materials
- No MIM parts—all components precision-manufactured in-house
- Springs and fasteners in 17-4 stainless steel and certified mil-spec steel
- Includes trigger, hammer, selector, bolt catch, magazine catch, and all pins and springs
- American-made quality for AR-10 lower assembly
- Builder kit format—you handle the assembly
Specifications
| Platform | .308 AR (AR-10) |
| Type | Lower Receiver Parts Builder Kit |
| Trigger Included | Yes |
| Hammer Included | Yes (AR15-pattern with J spring) |
| Selector/Safety | Yes |
| Bolt Catch Assembly | Yes (complete with spring, buffer, screw) |
| Magazine Catch | Yes (with aluminum button) |
| Pistol Grip | A2-style, black plastic |
| Detent Springs | Multiple (selector, takedown, mag catch) |
| Takedown Pins | Front and rear pivot pins included |
| Manufacturer | Luth-AR LLC (USA) |
Frequently Asked Questions
Will this kit work with my AR-10 lower receiver?
Yes—this kit is specifically designed for .308 AR-10 platform lowers. The parts are sized and configured for that platform, so they won't work in an AR-15.
Is assembly included, or do I need to assemble it myself?
This is a builder kit, meaning the parts are supplied unassembled. You'll be responsible for installing them into your stripped lower receiver. If you want a fully assembled option, look for Luth-AR's complete lower parts kit instead.
What exactly comes in the builder kit?
The kit includes the trigger, hammer, selector/safety, bolt catch (with spring and buffer), magazine catch (with aluminum button), all takedown and detent springs, front and rear pivot pins, hammer/trigger pins, pistol grip with bolt and washer, and all necessary fasteners. Refer to the parts list for the complete inventory.
Are these parts MIM or investment-cast?
Luth-AR produces these components through investment casting and precision machining—no MIM parts. Springs are 17-4 stainless steel or certified mil-spec steel wire, heat-treated to mil-spec standards.
