The SIG SAUER MCX-SPEAR SBR is a semi-automatic short-barreled rifle chambered in 6.8x51mm with a 13″ cold-hammer-forged threaded barrel and an included 20-round steel AR-10 magazine. It ships in a coyote anodized receiver finish with a polymer grip and a Magpul push-button folding SL-M stock for compact storage. Controls are fully ambidextrous and the rifle incorporates a free-floating M-LOK handguard and an adjustable two-position gas valve.
Key Specifications
- The rifle is chambered in 6.8x51mm.
- The barrel measures 13 inches and is described as cold hammer-forged steel with threading.
- The magazine capacity is 20 + 1.
- The action type is Semi-Auto.
- The trigger is a Sig Two-Stage Matchlite Duo.
- The stock is a Magpul Push-Button Folding SL-M design.
- The handguard uses an M-LOK interface for accessories.
- The muzzle device/thread pattern is 5/8×24.
- The listed weight with magazine is 8.9 lbs.
- The listed rate of twist is 1:7.
Built to the same design lineage as the MCX-SPEAR family, this short-barreled configuration provides a compact, modular platform while retaining many of the system features used by modern service-caliber designs, including ambidextrous controls, a folding stock and an adjustable gas system. The platform also supports caliber-conversion capability as described in the manufacturer’s materials.
Product information is supplied by the manufacturer and/or distributor and may be automatically formatted or enhanced using AI for clarity and consistency. While we strive for accuracy, specifications, features, and included items may change without notice. Always verify details using the manufacturer’s official documentation and the information shown on this product page before purchase or use.
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