SIG MCX Spear
SIG Sauer Inc. · Assault Rifle · In Production · 2022
Also known as: XM5, XM7, M7, NGSW-R
Overview
The SIG MCX Spear is a select-fire assault rifle chambered in 6.8x51mm (.277 SIG Fury), produced by SIG Sauer Inc.
Specifications
| Weight (empty) | 3800 g (134.0 oz) |
| Weight (loaded) | 4460 g (157.3 oz) |
| Overall Length | 973 mm (38.31") |
| Folded Length | 699 mm (27.52") |
| Barrel Length | 330 mm (12.99") |
| Action Type | Gas Operated Short Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Two Stage |
| Magazine Capacity | 20 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 838 m/s (2749 fps) |
| Muzzle Energy | 2570 J (1896 ft·lbf) |
| Effective Range | 600 m (656 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Cerakote |
Calibers
- 6.8x51mm (.277 SIG Fury) · primary — also known as .277 Fury, .277 SIG Fury, 6.8x51mm Common Cartridge, 6.8 CT
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Safety Selector, Firing Pin Block
- Features: Folding Stock, Adjustable Stock, Select Fire, Suppressor Ready, Free Floating Barrel, M Lok Handguard, Ambidextrous Controls, Quick Change Barrel, Multi Caliber, Picatinny Rail, Rotating Bolt, Short Stroke Gas Piston
Variants
- M7 (XM7) — Military
- SIG MCX Spear LT — Lightweight
- SIG MCX Spear 7.62 NATO — Caliber Conversion
- SIG MCX Spear 6.5 Creedmoor — Caliber Conversion
Service history
Operators
- United States Army · adopted 2022 · as M7
- 75th Ranger Regiment · adopted 2023 · as XM7
- 101st Airborne Division · adopted 2024 · as XM7
Production
Production years: 2022-present
Initial 10-year US Army contract awarded April 2022; fielding began 2024 with 101st Airborne Division
Origin
Country of origin: United States
Designer: SIG Sauer Engineering Team
Notes
The NGSW program was driven by the need to defeat near-peer adversary body armor at extended ranges, which 5.56mm NATO could not reliably accomplish. The 6.8x51mm cartridge uses a revolutionary hybrid case with a steel base and brass body, allowing safe operation at 80,000 PSI chamber pressure - far exceeding conventional cartridges. The civilian MCX Spear is semi-automatic only. In September 2025, SIG Sauer presented an improved M7 with a shortened 10.5-inch barrel and lightened internals. The rifle is designed to be used with the XM157 Fire Control optic, an integrated next-generation squad weapon fire control system with ballistic computer.
Background
The SIG MCX Spear represents the most significant change in US infantry small arms since the adoption of the M16 in the 1960s. The NGSW program was born from the realization that 5.56mm NATO could not reliably defeat modern body armor worn by near-peer adversaries. The revolutionary hybrid-case ammunition operates at chamber pressures 33% higher than conventional cartridges, delivering rifle performance previously only achievable with much larger weapons.