What it is
AOP-2310 is a NATO Allied Ordnance Publication, promulgated as Edition A, Version 1 in June 2020, and its own cover page names it as exactly that. Its stated aim is direct: "the aim of this standard is to standardize 7.62 mm x 51 Ammunition and Link designs to ensure functional interchangeability between NATO Forces on the battlefield." It covers combat ammunition and links only; blank and training cartridges are explicitly outside its scope.
Like every Allied Publication, AOP-2310 does not bind by existing. The agreement of NATO nations to use it "is recorded in STANAG 2310," and it is that STANAG a nation ratifies, with reservations recorded against it where a nation cannot meet the requirement. Albania, for example, is recorded as unable to produce 7.62 mm x 51 ammunition at all. AOP-2310 reaches a manufacturer only once a national ordnance authority or a contract requires a design to carry NATO Qualification against it.
How interchangeability is actually established
AOP-2310 is a specification, not a test method. It does not describe how to measure pressure, velocity, or any other characteristic itself; for every performance category it points to a specific volume of AEP-97, the Multi-Calibre Manual of Proof and Inspection, which carries the test procedures. The document states this relationship plainly: interchangeability "is understood if the ammunition is in conformance with the performance, functioning and safety criteria as detailed in AEP-97." A reader who expects AOP-2310 alone to define how a design is tested will not find it here.
What the technical performance requirements cover
Chapter 2 organises the specification into twenty-one named categories, each tied to its own AEP-97 volume: pressure, velocity, action time, function and casualty, environmental performance, linked ammunition behaviour, barrel erosion, fouling, smoke and flash, precision, terminal effects, trajectory match, tracer performance, residual stress, primer sensitivity, bullet extraction, propellant and primer mix composition, waterproof performance, packaging and storage, marking, and the qualification route for designs other than ball and tracer. Annex A adds standardization drawings and Annex B a requirements table that restates the same twenty-one categories against their AEP-97 volumes.
This page does not reproduce the numeric thresholds, dimensions, or test conditions those chapters and annexes set out. They describe how the ammunition is made and functions, and that is precisely the specification detail a design engineer works from directly in the document, not through a secondary summary.
What NATO deliberately does not specify
Two points in AOP-2310 are worth knowing because they cut against what a reader might assume. Several link-specific requirements carry no NATO-set threshold at all. On salt corrosion, the document says "there are no specific NATO requirements for salt corrosion of the links for the linked ammunition to be considered NATO interchangeable"; the same pattern, clause by clause, leaves cartridge stripping, dimensional characteristics and visual inspection of links to each nation's own specification too, and a nation submitting linked ammunition instead provides its own Certificate of Conformity against that national specification. And on propellant and primer composition, NATO is explicit that it "does not specify the chemical composition" for a design submitted for qualification. Once that design is qualified, however, every subsequent production run bearing the NATO Symbol of Interchangeability has to match the composition identified in the original Qualification Approval sample. Annex A's own drawings carry a matching caution: they are for reference only and are not to be used for manufacture, with AEP-97 Volume 6 named as the actual manufacturing reference.
Qualification, not acquisition
A design that is submitted and tested successfully is "awarded" NATO Qualification for that nature of ammunition, letting NATO Member Forces apply the NATO Symbol of Interchangeability to it. Qualification is awarded per nature of ammunition, not per individual link type: a linked configuration needs both the ammunition and the link to meet the appropriate requirements, but if the link later fails a Production Test, the ammunition itself keeps its qualified status. AOP-2310 is careful to separate this technical finding from a procurement decision: "this standard by itself should not be used for acquisition purposes." Qualification tells a nation a design meets the interchangeability requirement. It is not, by itself, the decision to buy it.
Where it sits alongside AEP-97 and STANAG 2310
STANAG 2310 is the agreement nations ratify; AOP-2310 is the Allied Publication issued under its cover and carries the actual technical content. AEP-97 carries the test procedures and pass criteria that every one of AOP-2310's twenty-one performance categories defers to. AOP-2310 also points to AOP-2 for marking NATO ammunition and its packaging.