Ar Buffer To Picatinny Railkns Stock Adapter W/Flange

The KNS Precision AR Buffer to Picatinny Rail Stock Adapter with Flange is a modular solution for shooters who want to mount Picatinny-compatible stocks and braces on platforms that use AR-15 style buffer tubes but don't mechanically require them for operation. If you're running a firearm where the carrier and buffer tube don't extend past the receiver ring, this adapter lets you swap to modern Picatinny-mounted accessories—like SIG MPX folding stocks or Picatinny braces—without the bulk or footprint of a traditional buffer tube.

The two-piece design is straightforward: an externally-threaded adapter plug screws into your firearm's threaded buffer socket, while a Picatinny rail section slides into a slot on the plug. A single hex-socket bolt and lock washer secure everything together. The integrated flange at the base of the Picatinny plate maintains compatibility with standard AR-15 takedown pins, detents, and springs on traditional lower receivers, so you're not locked into proprietary hardware.

This adapter is built for non-standard AR platforms and specialized builds—not for conventional AR-15 rifles running standard buffer tubes and carriers. If your rifle's buffer tube and carrier protrude past the receiver ring, this isn't the right fit. But for the niche it's designed for, it opens up genuine modularity and lets you run the stock or brace that works best for your shooting style.

Key Features

• Converts buffer tube mounting to Picatinny rail compatibility
• Allows use of modern folding stocks and Picatinny-mount braces
• Integrated flange supports standard AR-15 takedown hardware
• Two-piece modular design with tool-free assembly
• Works with traditional AR-15 lower receivers

Frequently Asked Questions

Will this work on my standard AR-15?

No. This adapter is not compatible with standard AR-15 rifles that use conventional buffer tubes and carriers. It's designed specifically for platforms where the carrier and buffer tube don't protrude past the receiver ring and where a buffer tube isn't mechanically required.

What stocks and braces can I mount with this adapter?

Any Picatinny-rail-compatible stock or brace will work, including SIG MPX folding stocks and other Picatinny-mounted options. As long as the accessory uses Picatinny slots, it will attach to the rail section of this adapter.

Do I need special hardware to install it?

No. The kit includes a hex-socket bolt and lock washer for assembly. The flange design preserves compatibility with standard AR-15 takedown pins, detents, and springs, so you don't need proprietary parts.

What's included in the kit?

The adapter kit consists of two parts—the externally-threaded adapter plug and the Picatinny rail section—plus a hex-socket bolt and lock washer for assembly.