KAK Industries recently released their new AR-15 buffer tube adapter for the Sig Sauer MPX pistols. Their new adapter allows you to mount any AR-15 buffer tube to your MPX pistol, you can go with a pistol specific buffer tube and fit a Sig brace or one of those fancy new Shockwave braces. Or you can go the SBR route and put on a stock. The KAK mount is made out of 6061-T6 aluminum and installs onto the rail on the rear of the MPX pistol with 3 cross bolts. They retail for $43 at kakindustry.com.
ENABLES THE ADDITION OF AN AFTERMARKET ARM BRACE OR
OTHER PISTOL BUFFER TUBE ACCESSORY
ADAPTER IS MADE OF 6061 T6 ALUMINUM, FLAT BLACK ANODIZED
IF USING A CARBINE STYLE CASTLE NUT BUFFER TUBE
THERE ARE TWO THREADED ALIGNMENT HOLES (10×32 THREAD) FOR TUBES
THAT USE A NOTCH FOR INDEXING. A 3/16 HALF DOG SOCKET SET SCREW
WOULD BE USED FOR PROPER INDEXING.