Mil-Spec AR-10 Butt Stock Build Kit

Complete your AR-10 lower receiver with the Mil-Spec AR-10 Butt Stock Build Kit from Miami Shooters Supply. This kit provides all the essential components you need to install a functional and reliable butt stock on your large-frame AR platform rifle. Whether you’re assembling a new precision rifle, a dedicated DMR, or simply replacing worn parts, this bundle ensures you have the correct, mil-spec hardware for a solid lockup. We ship fast so you can get back to building.

Key Features

• Includes all necessary mil-spec internal components: buffer tube, castle nut, end plate, buffer, buffer spring, and stock.
• Manufactured to U.S. military specifications for consistent dimensions, threading, and reliable performance.
• Provides a complete foundation for attaching any mil-spec compatible AR-10 or SR-25 pattern stock.
• Correct rifle-length buffer and spring designed for the .308 Winchester / 7.62x51mm cartridge’s longer bolt carrier travel.
• All parts are properly heat-treated and finished to resist wear and corrosion.

Built For

This kit is ideal for the builder assembling an AR-10 from a stripped lower receiver who needs the complete stock assembly package. It’s also a perfect solution for anyone upgrading from a commercial-spec tube or replacing individual components that have seen heavy use, ensuring all parts work together seamlessly.

Specifications

• Compatibility: Designed for AR-10, SR-25, and other large-frame AR platform rifles in .308 Winchester/7.62x51mm.
• Buffer Tube: 7075-T6 aluminum mil-spec diameter receiver extension.
• Buffer: Rifle-length, appropriate weight for .308 caliber.
• Finish: Type III hardcoat anodized for durability.
• Includes: Buffer tube, castle nut, end plate, buffer, buffer spring, and adjustable butt stock.

FAQ

Is this kit compatible with a standard AR-15?
No. The buffer, buffer spring, and internal dimensions are specific to the larger AR-10 platform and will not function correctly in an AR-15.

Does the stock included have a QD sling swivel socket?
The included stock is a standard 6-position adjustable model; specific features like QD sockets may vary, but it will have a sling loop. Check product images for the exact configuration.