This is a new Sig Sauer MCX-SURG complete suppressed upper receiver chambered for 5.56 NATO bundled with an MCX SPEAR pistol lower receiver. The MCX-SURG Upgrade Kit was specifically engineered as a drop in upgrade for a standard M4A1 lower, converting any standard Mil-Spec AR rifle into a next-generation MCX. It features an 11.5-inch threaded barrel, direct thread 7.3" reduced blow-back Inconel suppressor with Titanium heat shield, M-LOK handguard, adjustable gas block, full length picatinny rail for optic mounting, and an ambidextrous charging handle. This upper includes a complete MCX upper receiver group, direct thread Inconel suppressor, removable titanium cage, SD handguard, low profile handguard, and an AR-15 folding stock with adapter kit.
The complete pistol receiver features lightweight aluminum construction with a Coyote finish, ambidextrous safety selector, flat blade match trigger, polymer grip, and a rear-mounted picatinny rail for stock mounting.
Both items are factory new and unfired with the lower receiver being separated from a complete pistol (RMCX-762R-11B-LT).
Sig Sauer
