NATO standardization is built around interoperability rather than a single corporate owner. NATO describes STANAGs as agreements by member countries to implement standards so allied forces can use compatible equipment, methods, and support. In small-arms ammunition, that structure lets different producers supply cartridges such as 5.56x45mm NATO, 7.62x51mm NATO, and 12.7x99mm NATO while keeping weapons, links, packaging, and proof expectations aligned across armies.
The industrial base includes national ammunition plants, private ammunition companies, and licensed or transfer-of-technology production lines. Public sources document several examples: FN Herstal identifies the 5.56x45mm SS109 and 7.62x51mm NATO lineages with NATO standard adoption dates, FN also describes its role in the 12.7 NATO STANAG reference-round system, the U.S. Army documents NATO-qualified Cal .50 M33 lots with NATO interchangeability markings, and Nammo publishes current 5.56 mm, 7.62 mm, and 12.7 mm product families for military users.
NATO-standard small-arms ammunitionInterchangeable cartridge productionAmmunition proof and qualificationLinked heavy-machine-gun ammunitionLicensed and national production lines
Scope note: NATO-standard ammunition is produced by multiple national arsenals and commercial manufacturers; the sources document standardization, representative cartridge families, and production-line examples rather than a single corporate owner.