Sig Sauer MCX-SPEAR LT Gen 3 5.56 NATO Semi-Automatic Rifle – FDE, Custom YHM 3-Port Brake, 16 in. Barrel
The MCX-SPEAR LT Gen 3 represents Sig Sauer’s latest evolution of the MCX platform, combining a cold-hammer-forged 16-inch barrel. Finished in Gen II IR-signature-reduced Flat Dark Earth Cerakote, this short-stroke, gas-piston rifle offers ambidextrous controls, a quick-change barrel system, and an upgraded Matchlite Duo two-stage trigger. A lightweight 13-inch free-float M-LOK handguard and Magpul MOE SL-K stock round out a set-up tailored for reliability, modularity, and fast handling.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent – clean, mirror finish, no signs of wear.
Bore Rifling: Excellent rifling – sharp lands and grooves.
Specific Condition Notes: Minor, superficial scratches and blemishes are present on the exterior surfaces. The bore remains clean and shiny.
What’s Included
- SIG Sauer MCX-SPEAR LT owner’s manual
- Adjustable two-point sling (black)
- Polymer vertical foregrip (installed)
- Yankee Hill Machine 3-port muzzle brake (pinned & welded)
- (2) 30-round D&H SureFeed E2 aluminum magazines
The heart of this rifle is its 16-inch cold-hammer-forged, chrome-lined barrel.
Sig’s two-position adjustable short-stroke gas-piston system keeps fouling out of the action and lets you tune the rifle for suppressed or unsuppressed use. The barrel’s quick-change interface means caliber conversions are user-friendly, and the lower receiver is factory-marked “SIG MCX MULTI-CALIBER” to reflect that versatility.
Controls are fully ambidextrous, including the safety selector, paddle-style magazine release, bolt catch, and non-reciprocating charging handle with extended latches. A flat-face Matchlite Duo trigger breaks cleanly at roughly 4.5 pounds, giving the shooter a predictable two-stage pull.
The 13-inch free-float alloy handguard offers a full-length Picatinny top rail and M-LOK slots at 3, 6, and 9 o’clock for accessory placement without adding unnecessary weight. A Magpul MOE SL-K six-position collapsible stock and reduced-angle polymer pistol grip complete the ergonomic package.
Finished in Gen II Flat Dark Earth Cerakote that reduces IR signature, the forged 7075-T6 aluminum upper and lower receivers provide durability and corrosion resistance while matching the color of the stock and grip for a cohesive appearance.