SIG SAUER MCX SPEAR-LT SBR RMCX-762R-11B-LT-SBR — Description

The SIG SAUER MCX SPEAR-LT SBR RMCX-762R-11B-LT-SBR is a compact 7.62x39mm semi-automatic short-barreled rifle (SBR) built on SIG Sauer’s next-generation MCX SPEAR-LT modular platform. Designed for maneuverability and reliability, this configuration features an 11.5-inch barrel, Coyote finish, folding stock, lightweight M-LOK handguard, and a short-stroke gas piston operating system.

The SPEAR-LT platform improves upon previous MCX generations with enhanced modularity, ambidextrous controls, an improved receiver design, and compatibility with modern accessories. The 7.62x39mm version uses a dedicated 28-round magazine and provides the familiar ballistic performance of the cartridge in a refined SIG Sauer piston-driven rifle system.

The SBR configuration combines compact dimensions with the versatility of a folding stock system and free-floating aluminum M-LOK handguard. The rifle is designed for users who want a lightweight, adaptable platform with modern ergonomics and the reliability advantages of a piston-driven action.

SIG SAUER MCX SPEAR-LT SBR RMCX-762R-11B-LT-SBR — Specifications

Manufacturer: SIG SAUER
Model: MCX SPEAR-LT SBR
Model Number: RMCX-762R-11B-LT-SBR
Caliber: 7.62x39mm
Action: Semi-automatic
Operating System: Short-stroke gas piston with rotating bolt
Platform: SIG MCX SPEAR-LT modular rifle system

Barrel Length: 11.5 inches
Barrel Twist Rate: 1:9.5″
Barrel Type: Cold hammer-forged barrel
Receiver Material: Aluminum
Finish: Coyote finish
Handguard: Free-floating aluminum M-LOK handguard
Stock: Folding stock
Magazine Type: SIG 7.62x39mm detachable magazine
Magazine Capacity: 28 rounds
Controls: Fully ambidextrous controls
Gas System: Adjustable gas piston system
Rail System: Full-length Picatinny top rail
Overall Length: Approx. 29.25 inches extended
Weight: Approx. 6.9 lbs (without magazine)

Key Features

• 7.62x39mm chambering
• 11.5-inch SBR configuration
• Short-stroke gas piston operating system
• Coyote finish
• Folding stock for compact storage and transport
• Free-floating M-LOK handguard
• Fully ambidextrous safety, magazine release, and bolt controls
• Dedicated 28-round magazine system
• Cold hammer-forged barrel
• Optics-ready Picatinny receiver rail
• Modular MCX SPEAR-LT architecture
• Improved reliability and reduced fouling compared with direct-impingement systems

Package typically includes:

• SIG SAUER MCX SPEAR-LT 7.62x39mm SBR
• Folding stock assembly
• 28-round magazine
• M-LOK handguard system
• Owner’s manual and safety documentation