SIG Sauer MCX Full-Auto 9mm Upper Receiver No Handguard

For sale is a used SIG Sauer upper receiver assembly sourced from a full-auto SIG. This is the upper only as shown in the photos—no lower receiver, no handguard, and no other parts included unless specified by seller.

Features & Condition:

• Black anodized aluminum upper with continuous top Picatinny (M1913) rail
• Flip-up rear iron sight mounted (folds and adjusts)
• Ejection port with dust cover
• Barrel installed with multi-port muzzle device (flash hider/compensator style); shows use-related discoloration and finish wear
• Receiver shows typical handling scratches and wear consistent with prior use
• Short-stroke piston / MCX-style platform features visible

Notes for Buyers:

• Sold as upper receiver group only. Buyer is responsible for compatibility, function, headspace, and all legal compliance.
• Barrel length appears shorter than a standard rifle configuration in the photos—verify exact measurement. Short-barreled configurations may require NFA registration (Form 1/SBR, etc.) depending on final configuration and jurisdiction. All NFA rules apply where relevant.
• Compatible with appropriate SIG MCX or adapter-equipped AR-pattern lowers (confirm fit). Full-auto capability depends on the lower receiver (the upper itself is not the registered machine gun component in typical U.S. AR/MCX setups).
• Condition is used/as-is. No returns or guarantees of function. Inspect thoroughly or have a qualified gunsmith evaluate.

Photos show multiple angles of the receiver, barrel, muzzle device, and sight.