SIG MCX Spear LT
SIG Sauer Inc. · Carbine · In Production · 2022
Also known as: MCX-Spear LT, SIG Sauer MCX Spear LT
Overview
The SIG MCX Spear LT is a gas-piston-operated carbine and the third-generation evolution of SIG Sauer's MCX platform, introduced in 2022 as a lighter civilian and duty companion to the 6.8mm MCX-Spear that won the U.S. Army Next Generation Squad Weapon program. It uses a short-stroke gas piston and an internal recoil system that eliminates the AR-style buffer tube, allowing a side-folding stock. The Spear LT is offered with interchangeable 9, 11.5, and 16-inch barrels across 300 BLK, 5.56 NATO, and 7.62x39mm, with fully ambidextrous controls, a free-floating M-LOK handguard, an SDI M400-style lower that accepts AR-15 triggers, and a QD suppressor-ready flash hider.
Specifications
| Weight (empty) | 3000 g (105.8 oz) |
| Weight (loaded) | 3400 g (119.9 oz) |
| Overall Length | 870 mm (34.25") |
| Barrel Length | 406 mm (15.98") |
| Action Type | Gas Operated Short Stroke Piston |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Action |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 940 m/s (3084 fps) |
| Muzzle Energy | 1767 J (1303 ft·lbf) |
| Effective Range | 500 m (547 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Frame Material | Aluminum |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Coyote Anodized |
Calibers
- 5.56x45mm NATO · primary · 5.56mm NATO — also known as 5.56 NATO, 5.56x45mm, .223 Remington (chamber compatible)
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Manual Safety
- Features: Short Stroke Gas Piston, Buffer Tubeless Internal Recoil System, Side Folding Stock, Ambidextrous Controls, Interchangeable Barrels, Free Floating Handguard, M Lok Handguard, Flatblade Match Trigger, Optics Ready, Qd Suppressor Ready Flash Hider
Variants
- SIG MCX Spear LT 11.5" — Short Barrel
- SIG MCX Spear LT 9" 300 BLK — Pdw
Production
Production years: 2022-present
In current production; offered in multiple barrel and caliber configurations
Origin
Country of origin: United States
Designer: SIG Sauer
Notes
Civilian models ship semi-automatic; the underlying MCX platform supports select-fire configurations for military and law enforcement. Overall length and weight cited are for the 16-inch 5.56 NATO configuration. Barrels are user-interchangeable, allowing caliber and length changes on the same receiver.
Background
The Spear LT name links the rifle to the MCX-Spear (XM7/M7), SIG Sauer's winning entry in the U.S. Army Next Generation Squad Weapon competition, positioning the lighter 5.56 carbine as a commercially accessible member of the same family.