SIG SAUER | MCX Stock Adapter Kit | Black

SIG's MCX Stock Adapter Kit is the genuine factory part that lets you upgrade an MCX to run a folding stock assembly instead of the fixed configuration it may have shipped with -⁠- a rail attachment, bumper housing, recoil bumper, and shoulder screw, all built to the exact tolerances the MCX platform needs. It's specifically for folding stocks, not collapsible braces, and the aluminum Picatinny‑style adapter installs to convert the rifle's rear interface cleanly. The correct factory hardware for a real MCX stock upgrade, not a universal adapter hoping to fit.