What it is
STANAG 2310 is the NATO Standardization Agreement covering the technical performance specification for the interchangeability of 7.62 mm x 51 ammunition and links. This is Edition 4, promulgated 5 June 2020, superseding STANAG 2310, Edition 3 (the document does not give a date for that earlier edition).
A STANAG is not the specification
A STANAG is the agreement by which NATO nations commit to implement a standard, not the technical specification itself. STANAG 2310's own text is short and administrative: an aim, one interoperability requirement, and the ratification, reporting and review machinery. The 7.62 mm x 51 ammunition and link characteristics named in its title are specified in a separate publication, AOP-2310 Edition A, which the STANAG names as the standard participating nations agree to implement. Anyone actually designing, specifying or testing those characteristics needs AOP-2310's own text, and AEP-97 for how ammunition and links are proven against it, not this cover agreement.
What it commits nations to
The stated aim is interoperability: "to standardize, for the use of the NATO Armed Forces, the essential characteristics of 7.62 mm x 51 ammunition and links to ensure interchangeability on the battlefield". Participating nations "agree to implement the following standard", named as AOP-2310, Edition A.
Who it binds, and how
STANAG 2310 binds nations, not suppliers. It is effective "upon receipt and ready to be used by the implementing nations and NATO bodies", while partner nations are only "invited to adopt this STANAG" rather than bound by ratification. Implementation is a further, distinct step: the STANAG "will be considered to have been implemented when ratifying nations have introduced into their armed forces ammunition and/or linked ammunition which has met the requirements of this STANAG in AOP-2310 and the Multi-Calibre Manual of Proof and Inspection Procedures (AEP-97)". A shortcut is explicitly ruled out: "reference to the STANAG alone as the National Implementing Document does not meet this intent" - a nation has to hold documentation demonstrating the ammunition actually met the requirements, identified as its National Implementing Document. A supplier meets STANAG 2310, or the AOP-2310 characteristics it covers, only where a contract or tender says so; the document sets no obligation reaching a supplier directly, and no compliance date of its own.
How it's evaluated
STANAG 2310 describes no certification scheme and no audit. What it describes is nations reporting to NATO: national decisions on ratification and implementation are provided to the NATO Standardization Office, and: "The national responses are recorded in the NATO Standardization Document Database (NSDD)". Nobody is "STANAG 2310 certified", and the document never uses that language. Where an ammunition or link design is actually tested for interchangeability, that proof and inspection work runs under AEP-97 and AOP-2310, not this cover agreement.
Standards it references
STANAG 2310 covers AOP-2310, the publication that carries the ammunition's own performance requirements. Its related-documents list also names STANAG 2953 (Identification of Ammunition) together with AOP-02, AAP-06 (the NATO Glossary of Terms and Definitions), and STANAG 4823 (the Multi-Calibre Manual of Proof and Inspection for NATO small arms ammunition) together with AEP-97, noted in this edition as "currently under ratification" at the time of writing. Reviews of STANAG 2310 itself, and national reporting on ratification, implementation and adoption, run under AAP-03.