Sig Sauer MCX Rattler LT 5.56 NATO AR Pistol, 7.75 in Cold Hammer Forged Threaded Barrel, Matte Black
The Sig Sauer MCX Rattler LT in 5.56mm NATO pairs a compact 7.75 in barrel with a short-stroke gas piston system and full ambidextrous controls. This LT submodel features an extended free-float M-LOK handguard with a continuous 1913 Picatinny top rail, lightweight aluminum receivers, and U.S.-applied markings. It is a recent release within the MCX Rattler series.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The barrel has an exposed threaded muzzle and no muzzle device installed. Do not fire or use this firearm until a proper muzzle device, faux suppressor, or suppressor is installed. Sold AS-IS.
What’s Included
- Original box
- 1x 30-round magazine (Magpul PMAG, polymer AR-pattern, marked 300 BLK)
This MCX Rattler LT is chambered in 5.56mm NATO and uses a semi-automatic, short-stroke gas piston action for consistent operation in a compact format. The 7.75 in carbon steel barrel is cold hammer forged and threaded, with the exposed muzzle threads ready for a user-installed device.
The upper is marked 'RATTLER,' and the receivers carry 'SIG SAUER INC NEWINGTON NH USA' and 'SIG MCX MULTI-CALIBER' rollmarks. Both upper and lower are aluminum alloy with a matte black anodized finish.
An extended-length, octagonal cross-section free-float M-LOK handguard runs forward of the receiver, integrating a continuous 1913 Picatinny top rail from receiver to handguard. An ejection-port cover is present, and this configuration omits a forward assist.
Controls are thoughtfully executed: ambidextrous safety selector, ambidextrous bolt catch/release, and an ambidextrous dual-latch charging handle, with a right-side magazine release. A QD sling socket sits at the rear of the lower receiver, and the rear 1913 Picatinny end-cap interface is configured for attaching a folding stock or brace (not included).
The pistol accepts AR-15 pattern detachable magazines with a stated 30+1 capacity. One 30-round Magpul PMAG is included and is marked 300 BLK. As model-line context, the MCX Rattler platform has documented U.S. SOCOM evaluation and CPDW program selection.