Sig Sauer MCX-Rattler LT Pistol PCB – .300 AAC Blackout
The latest evolution of Sig’s renowned MCX platform, the compact Rattler LT marries battle-proven engineering with civilian practicality in a 6.75-inch-barreled, brace-equipped format. Purpose-built for suppressed .300 BLK performance, it delivers PDW handling, a fully ambidextrous control set, and Sig’s crisp Matchlite Duo flat-blade trigger—attributes that make this specific pistol as collectible as it is capable.
Condition
Overall condition is Excellent. Metal surfaces show only faint, honest evidence of prior handling; anodizing remains deep matte black with no thinning or scratches worth noting. The cold-hammer-forged bore is mirror bright with sharp, intact lands and grooves, earning an Excellent rating. All controls lock up positively, and brace articulation is tight with no wobble.
What’s Included
• Factory-installed Sig Pivoting Contour Brace (side-folding, 1913 interface)
• Magpul PMAG 30 AR 300 B Gen M3 magazine
• M-LOK polymer angled foregrip (installed)
Born from the USSOCOM PDW solicitation, the MCX-Rattler LT distills the features operators demanded into a civilian-legal pistol. Its short-stroke, two-position adjustable gas piston keeps the action clean—especially when shooting suppressed through the included QD flash-hider. The 7075-T6 forged receivers share MCX modularity, allowing barrel or hand-guard swaps without a gunsmith. A 1:5″ twist stabilizes everything from 110-grain supersonic to heavy 220-grain subsonic loads, while the 5⁄8-24 muzzle threads accept most common .30-caliber suppressors.
Controls are mirrored left and right—magazine release, selector, bolt catch, and charging handle—so transitions feel natural whether you run strong- or support-side. The Matchlite Duo trigger breaks at roughly 4.5 lb with a predictable two-stage wall, ideal for accurate shot placement from such a compact envelope. Weighing just 5.1 lb and measuring 17.1″ folded, it stows effortlessly in a pack or vehicle yet opens to a 25.4″ overall length for full-size handling.
Integral safety is provided by the ambidextrous selector switch: 0° safe, 90° fire. The flat trigger face encourages straight-back press, reducing the likelihood of lateral deviation—especially helpful on short PDW receivers.
If you have been looking for a purpose-built .300 BLK platform that excels both suppressed and unsuppressed, the condition, features, and provenance of this Rattler LT make it a standout choice.