KNS Picatinny Stock Adapter / Sig Sauer Folding M4 Stock Kit


SKU: 119 Series Combo Categories: , ,


Sig Sauer factory replacement collapsible stock assembly installs easily on your ACE or bufferless AR (like the Brownells BRN-180 system) receiver with a receiver mounted 1913 rail interface. This stock assembly gives you the ability to install standard AR-15/M4 type buttstocks on your gun via the mil-spec diameter extension tube while giving it the ability to fold.

The AR/MCX Stock Adapter allows the user to mount a picatinny-style stock attachment (such as the SIG MPX folding stock or brace) in place of an AR15 style buffer tube. Many firearms utilize the buffer tube attachment of the AR15 in order to mount common stocks & braces, but do not mechanically require the tube for an in-line buffer spring. For these weapons, this product offers a modular alternative for attaching stocks or other accessories.

The kit is composed of two parts and an attaching bolt. The externally-threaded adapter plug fits into the threaded buffer socket or ring. The adapter rail section firs into the slot in the adapter plug and the two are secured to each other and the firearm by a hex-socket bolt and lock washer.

This product will not work with a standard AR 15 lower and the MCX upper and is intended only for applications where the carrier and buffer tube do not protrude past the receiver ring.

*NOTE: Standard configuration AR15 style rifles will not function using this product.

**NOTE: The key difference between the with-flange and without-flange adapters lies in the base of the picatinny plate. The with-flange has a shelf that allows the use of a standard takedown pin, detent, and spring on traditional AR15 lower receivers. The without-flange model omits this shelf and as such will not retain the takedown pin’s detent & spring in the rear of the AR15 receiver.

***Lower Receiver not included. Sorry, folks.


Patent No. #10,598,450

Additional information

Adapter Style

Galil Ace Picatinny Stock Adapter, AR/MCX Picatinny Stock Adapter WITH Flange, AR/MCX Picatinny Stock Adapter W/O Flange


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