SIG Sauer won the NGSW competition for the supply of a next-generation weapon system to the United States Armed Forces: an official press release was published on April 19th, 2022 the US Army website, announcing the award to the New Hampshire -based company of a 10-year firm-fixed-price follow-on production contract to for the manufacture and delivery of two Next Generation Squad Weapon variations and the 6.8 Common Cartridge Family of Ammunition.

Following 27 months of rigid trials and evaluation, SIG Sauer's submissions ended up on top against prototypes of assault rifles, squad automatic weapons, and relevant ammunition submitted for consideration by the Textron Systems company and by the Beretta - General Dynamics consortium – whose right were lately acquired fully by True Velocity. The value of the initial delivery order on the contract is $20.4 million for weapons and ammunition that will undergo testing. The contract includes accessories, spares and contractor support.

SIG Sauer's NGSW weapon system includes an assault rifle – based on the Company's own, tried and true MCX design – that received the official denomination of XM5; and a light machine-gun, now designated the XM250.

Both weapons fire a proprietary hybrid cartridge dubbed .277 FURY – also known in metric as 6.8x51mm – that is built around a proprietary two-piece case: a brass body and a separate stainless steel case held together by a locking washer. The combination is rated to handle 80,000 psi of chamber pressure, and the "6.8mm Common Cartridge Family of Ammunition" (as designated by the US Army) includes multiple types of tactical and training rounds that increase accuracy and are more lethal against emerging threats than both the NATO standard 5.56mm and 7.62mm ammunition

SIG Sauer's new XM5 rifle and XM250 machine-gun will not serve a complete replacement for the M4 carbine and the M249 SAW (FN Minimi) and M240 (FN MAG) machine-guns currently in service. Their first recipients will be the specialized units that are part of the US Army's Close Combat Force. Other armed services are however watching closely the progress of the NGSW program.

SIG Sauer's entries in the competition were immediately noticed by observers as being objectively the most effective, complete, and all-round best entrants in the NGSW program. The .277 FURY ammunition – whose design allows it to be lighter while at the same time extremely affective and not too much out of current industry standards – likewise turned out to be an overall better choice over the entries submitted by other competitors.

Additionally, SIG Sauer's XM5 assault rifle and XM250 machine-gun will be easily converted to the use of 7.62x51mm NATO ammunition, allowing the use of existing stocks of ammo to reduce training costs or to maintain the weapons operational on the field should the proprietary 6.8x51mm ammunition not be readily available.

The XM5 and XM250 will be paired with Vortex Optics' new XM157 fire control system, a ruggedized advanced fire control system that integrates a variable magnification optic (1-8x) with a backup etched reticle, laser rangefinder, ballistic calculator, atmospheric sensor suite, compass, Intra-Soldier Wireless, visible and infrared aiming lasers, and a digital display overlay. The US Department of Defense plans to acquire up to 250,000 XM157 fire control systems by the year 2032.

A civilian-grade version of the new XM5 assault rifle also already exists, dubbed the SIG Sauer MCX SPEAR semi-automatic rifle; it was first announced in a limited edition for the US commercial market in January 2022. Additionally, the SIG Sauer NGSW entries will also be available for potential Foreign Military Sales.