Production will take place at the Lake City Army Ammunition Plant, the only government-owned, contractor-operated small-caliber munitions manufacturing facility in the United States. These projects were assigned under Winchester’s $8 billion contract to operate the Lake City facility. Winchester Munitions took over the operation in Lake City in late 2020.
The NGSW program was created to replace the M4 Carbine, M249 SAW and M240 machine gun with 5.56×45 and 7.62×51 shells. Two weapons manufacturers, True Velocity (formerly LoneStar Future Weapons, General Dynamics) and Sig Sauer participate in the program. Other defense companies (Textron Systems, FN-America, and PCP Tactical) were excluded from the program between September 2019 and November 2021. The program is expected to cost $10 million the first year and $150 million the following year.

The NGSW program began in 2017 after the US Congress began testing the M4 and the 5.56×45mm NATO round for today’s effectiveness. They concluded that the M4 Carbine is still preferred by troops and also performs well under stress. Problems such as feeding problem using different ammunition types and magazines have been fixed. Despite this, the M4 still had difficulties penetrating the types of bulletproof vests used by Russian and Chinese troops, especially at longer distances. The program also took into account the experience of the US military in the Middle East, where guerrillas use weapons with larger projectiles and higher effective ranges, such as the AKM. Therefore, Congress began to replace the M4.
The US Army has issued a set of requirements for prototype NGSW weapons;
- Ability to fire 6.8 mm rounds
- Maximum length of 35 inches (890 mm)
- Maximum mass of 12 lb (5.4 kg) including attachments
- Ability to suppress targets from 3,900 ft (1,200 m), and ability to accurately fire on targets 2,000 ft (610 m) away.
- To be able to use the fire control systems of Small Arms.
- Developing new fire control systems that can be used in small arms weapons of the NGSW program.
Two companies participated in the competition: Vortex Optics and L3 Harris Technologies.