February 22, 2022
SIG Sauer’s submission to the U.S. Army’s Next Generation Squad Weapons (NGSW-R) program is based on the MCX platform, which was introduced commercially on Guns & Ammo’s March 2015 cover. The original MCX quickly earned a coveted reputation for its accuracy, reliability, and modularity, and quickly sought for military service. SIG Sauer can’t reveal its customers, but I’ll tell you that if you’re proficient at searching Google or DuckDuckGo (perhaps you follow certain militaries on Instagram), you’ll find pictures of MCX variants in use by the Danish Ministry of Defense (MOD), the London Metropolitan Police, Jordanian special forces, certain elements of the U.S. Army Special Forces and the British Special Air Service (SAS).
On October 4, 2018, the U.S. Army issued a draft of its solicitation for the NGSW-R, but the demand was centered around the development of a new 6.8mm cartridge that still needed development. Picatinny Arsenal developed the secretive 6.8mm projectile, which is unlike other 6.8mm bullets found in the 6.8 SPC and .270 Winchester, for example. Guns & Ammo’s research about the projectile leads us to believe that it will be like the Enhanced Projectile Round (EPR), which features an armor-penetrating bullet. Knowing that the 6.8mm bullet was designed by Picatinny arsenal for effectiveness at high velocities and long range, you deduce what its purpose is and why an existing commercial sporting round didn’t offer a solution. The aim of the U.S. Army’s 6.8mm projectile development was to optimize long-range effectiveness by providing the shooter with a purpose-built cartridge that produced high-enough velocities, more than anything in the U.S. market. However, the cartridge case must safely manage the increased pressures. SIG Sauer designed its solution in its hybrid-case 6.8x51mm cartridge that features a stainless-steel alloy base and rim attached to the brass-case body and neck.
Note, the 6.8x51mm round features a 51mm case, which suggests that it could be adapted to existing .308 Winchester-based receivers. However, SIG Sauer revisited its MCX and properly scaled it to safely operate the NGSW-submitted 6.8x51mm hybrid round. Simultaneously, SIG Sauer developed a commercial variant of the 6.8mm hybrid cartridge using the same projectile diameter to facilitate existing commercial .277-caliber bullets. The new .277 Fury offers many of the same features as the NGSW 6.8mm cartridge except at lower pressures and with a variety of sporting projectiles that are optimized for hunting applications. The first announced is a 150-grain Nosler AccuBond and 135-grain full-metal-jacket (FMJ).
“The revolutionary SIG Fury ammunition is the most technically advanced leap in small arms ammunition in over 150 years,” said Ron Cohen, president of SIG Sauer. “This turns your intermediate rifle platform into one with magnum performance without the added weight or length while still using 20-round magazines.”
The first commercial rifle to feed the .277 Fury is the MCX-SPEAR. For its ability to feed 51mm case-length ammunition, SIG Sauer introduced it also ready to accept the popular 6.5 Creedmoor and 7.62 NATO (.308 Win.) cartridges with a barrel change.
To chamber a round, the MCX-SPEAR offers rear- and side-located, non-reciprocating charging handles. A six-position folding stock, ambidextrous fire control, bolt catch, and magazine release continue the platform’s flexibility. The trigger is considered a two-stage “match,” and the gas piston features adjustments for two settings. The barrel and piston assemblies are protected by a lightweight, free-float handguard featuring multiple M-Lok slots for configuring accessories. Ready to accept optics and combinations of magnifiers, night vision or thermal optics, the top of the receiver wears a full-length Picatinny rail. Each rifle comes standard with two, 20-round magazines and include a suppressor.
The MCX-SPEAR is a special-edition variant of the MCX that will include SIG Sauer’s SLX suppressor. The SLX features a monolithic core construction of Inconel, which is capped to reduce muzzle flash. In addition to its sound mitigation and reduced flash performance, the SLX suppressor was designed in tandem with the MCX-SPEAR to reduce the shooter’s inhalation of toxic backflow of gases. It attaches to the barrel using either direct thread or SIG Sauer’s unique quick-detach (QD) system that’s easy and intuitive: Clutch-LOK QD.
The MCX-SPEAR has launched as a limited-run production model. These were pre-sold and allotted to certain dealers and distributors. Not many will be found at retail, but if you do see one, expect the price tag to be north of the $7,999 manufacturer’s suggested retail. SIG Sauer has informed Guns & Ammo that it will follow this launch with similar “tan-odized” models with chambers in the more ubiquitous 6.5 Creedmoor and .308 Winchester.
SIG Sauer MCX-SPEAR Rifle Specifications
- Type: Gas piston operated, semiautomatic
- Cartridge: .277 SIG Fury (6.8x51mm)
- Capacity: 20 rds.
- Barrel: 13 in., 1.7-in. twist., CHM steel, suppressed
- Suppressor: SIG Sauer SLX; Inconel Core; 7.49 in. (length) 1 lb., 3.4 oz. (weight)
- Overall Length: 34.1 in.
- Height: 7.97 in.
- Width: 2.98 in.
- Weight: 8 lbs., 5 oz.
- Stock: 6-position adjustable, Mil-Spec
- Handguard: M-Lok, aluminum
- Grip: Polymer
- Finish: Anodized, Coyote (aluminum)
- Trigger: Match, two-stage
- Safety: Two-position selector
- MSRP: $7,999
- Manufacturer: SIG Sauer, 603-610-3000, sigsauer.com
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