Sig MPX / MCX Compatible Accessories

Braces, stocks, and accessories compatible with the Sig MPX, MCX, and Rattler pattern.

69 products

About Sig MPX / MCX Compatible Accessories

Sig's MPX/MCX family shares a rear-interface pattern that makes it a natural fit for A3's modular system. Everything here is cataloged against the specific model — MPX, MCX, or Rattler — with fitment notes where generations differ.

For 1913-equipped models, the modular brace and HDA3 stock lines open up cross-platform compatibility: the same unit can move between your MCX and any other Picatinny-rear platform with an adapter swap selected at checkout.

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