Built for the FN-15. Right for Any Serious AR.

This isn’t a generic parts bin kit. This is the factory-original A2-style rifle buffer tube assembly produced specifically for the FN 15 platform. If you’re building a rifle with a fixed stock or converting a carbine, this is the correct kit. It provides the proper length, weight, and spring tension for reliable cycling with rifle-length gas systems.

The heart of the kit is the A1-style rifle-length buffer tube, machined from quality aluminum and designed to mate perfectly with an A2 fixed buttstock. We include the essential A2-style spacer to ensure a tight, rattle-free fit. The rifle buffer and spring are tuned to FN’s specifications, giving you the consistent bolt carrier group timing that these guns are known for.

You get the complete set: tube, rifle buffer, buffer spring, tube screw, and spacer. The components are built to last—aluminum for the housing and tube, durable steel for the spring and hardware. It’s a straightforward, no-nonsense upgrade or replacement part that just works.

Use this kit for your FN-15, or any mil-spec AR-15 lower receiver where you want the solid shoulder of a fixed stock. It’s compatible with .223 Remington, 5.56x45mm NATO, and .300 Blackout calibers on rifle-length systems. When you use factory parts, you eliminate guesswork. This kit gets your lower receiver ready for a proper rifle build.

What’s in the Kit:

• A1-Style Rifle Length Buffer Tube (Aluminum)
• Rifle Buffer
• Rifle Buffer Spring (Steel)
• Buffer Tube Screw (Steel)
• A2-Style Stock Spacer (Aluminum)

Specifications & Compatibility: