AEP-97 multi-calibre manual of proof and inspection for NATO small arms ammunition

What it is

AEP-97, an Allied Engineering Publication, is NATO's Multi-Calibre Manual of Proof and Inspection: one publication, in 27 volumes, that carries the test procedures behind six NATO calibre standards for small arms ammunition - AOP-4820, AOP-4172, AOP-4509, AOP-2310, AOP-4090 and AOP-4383. Each of those standards sets what a NATO-interchangeable ammunition design has to achieve; AEP-97 is where the test methods, equipment and sentencing rules that check a design against them actually live. Its own scope clause puts it directly: "The scope of this manual is to prescribe the uniform test methods, equipment and inspection procedures to assess the technical performance requirements for the following NATO small arms ammunition standards to ensure functional interchangeability on the battlefield."

A NATO nation commits to AEP-97 by ratifying one of those six calibre standards, not by AEP-97 existing on its own. Volume 1 sets out the mechanism directly: "In ratifying one or more of the above standards, nations agree to the following implementation mechanism applicable to the related calibre." What follows from that agreement is assessment of ammunition designs, testing at NATO-certified Test Centres, and use of the NATO Symbol of Interchangeability only for configurations that have actually been tested and authorised under this manual.

Who does what

AEP-97 addresses NATO nations, not manufacturers directly. Each nation acts through its own national delegate (Head of Delegation) to AC/225's Sub-Group 1 (SG/1) on Small Arms Ammunition Interchangeability, and testing itself is carried out at a Test Centre: "There are two NATO Regional Test Centres (RTC) certified for the conduct of NATO testing of small arms ammunition," and a nation may also run one or more National Test Centres of its own. A manufacturer's design reaches NATO testing only because its own nation puts it forward; the manual states that manufacturers and non-NATO nations cannot submit ammunition for NATO Qualification Approval or Production Testing independently.

The three levels of testing

Volumes 2 to 4 set out three distinct levels of NATO testing, each with its own volume and its own purpose. Qualification Approval "is conducted initially for each ammunition design submitted and serves to establish the compliance of those designs with the provisions of the appropriate standard." Production Testing runs on an ongoing basis once a design is in production, to confirm that manufacture continues to merit the NATO Symbol of Interchangeability and to catch an unauthorised change to the design or the process that makes it. Surveillance Testing runs on ammunition already qualified and already in national stockpiles, to check it still performs after time in storage. A failure at either of the later two stages can lead to the Symbol being suspended or withdrawn from that design. Volume 5 sets out who is responsible for running all of this: the National Delegate to SG/1, and the RTC Superintendent at each Regional Test Centre, who conducts and reports on testing, keeps the Test Centre's own equipment and standards current, and inspects a National Test Centre before it may be NATO-certified.

The supporting volumes

Volumes 6 to 11 hold material the individual test procedures rely on rather than a test procedure of their own. Volume 6 sets the test equipment specification and the visual standards used to classify a production defect. Volume 7 sets how a defect found outside the Function and Casualty Test is sentenced. Volume 8 governs NATO Reference Ammunition, the fixed baseline every test compares a submission against; its use is tightly controlled - "NATO Reference Ammunition shall NOT be used for national or contractor production control" - when stocks run low or deteriorate, SG/1 asks a nation to volunteer to produce a new lot, which SG/1 accepts only after both Regional Test Centres have tested it. Volumes 9 and 10 govern the family of weapons NATO nominates as the common rig every nation's ammunition is tested against for a calibre: how a weapon is introduced, replaced, upgraded, or withdrawn, and what the sponsoring nation has to keep supplying while it remains in that role. Volume 11 sets a four-category scheme for classifying a defect or incident found in any test, which the individual test-procedure volumes then apply when they decide whether a result passes.

The test-procedure volumes

Volumes 12 to 27 are sixteen self-contained procedures, one per characteristic: chamber pressure, velocity and action time; climatic storage conditioning; function and casualty firing; link performance; barrel erosion; smoke and flash; precision; terminal effects; trajectory matching; tracer performance; residual stress; primer sensitivity; bullet extraction; propellant and primer; waterproofing; and cook-off. None of them applies uniformly. Each volume's own applicability clause names which of the three test levels it covers and for which calibres, and only a handful - among them the pressure/velocity/timing test, the function and casualty test, the precision test and the tracer performance test - extend to Surveillance testing of ammunition already in service. Several of the rest apply only at Qualification Approval and Production, and a few apply at Qualification Approval alone.

How a submission is evidenced

A design does not arrive at a Test Centre on its own. Ammunition is eligible only once the submitting nation has procured or produced it for its own forces and declared it safe and suitable. It needs a build standard to test against, a government-approved laboratory's analysis report (a Certificate of Conformity stands in its place at the Production Test stage), and, for a number of link-related tests, a national Certificate of Conformity showing those tests met the submitting nation's own requirements rather than a NATO one. Pre-submission testing can happen at a National Test Centre or at a facility holding ISO 9001 certification: "The ammunition must have been successfully tested at a National Test Centre or an ISO 9001 certified facility (which could be the ammunition producer)."

What AEP-97 does not do

AEP-97 does not certify a company, and it names no accreditation scheme a supplier can join. A NATO Qualification - a NATO Design Number and the right to carry the NATO Symbol of Interchangeability - is awarded to an ammunition design by AC/225 (LCGDSS-SG/1), not to the company that made it. The organisational certification the manual does describe runs the other way: "Before proceeding to carry out testing in accordance with the requirements of AEP-97, the RTC/NTC must obtain NATO certification by AC/225(LCGDSS-SG/1) for specified calibres." That certifies the Test Centre's own competence to run AEP-97's procedures, never a supplier or a product line. Where a facility instead holds ISO 9001 certification for pre-submission testing, that certificate is held against ISO 9001, not against AEP-97.

Related standards

AOP-2, AAP-6 (NATO's glossary of terms and definitions), AAS3P-22, STANAG 2895 and NATO document AC/225 (Panel III-SP1) D/237 are all named in AEP-97's text. AAS3P-22 marks out what AEP-97 deliberately does not cover: safety and suitability assessment. STANAG 2895 is cited as a guide for climatic conditioning. AC/225 (Panel III-SP1) D/237 is cited as binding equipment drawings, reproduced in full as an annex to one of the test-procedure volumes. ISO 9001 appears too, as the alternative certification a pre-submission testing facility may hold, and STANAG 4297, AOP-15 and AOP-48 are cited together as reference material for shelf-life and storage assessment.

Standards it references

• STANAG 4090Binds
• AOP-4820Background
• AOP-4172Background
• AOP-4509Background
• AOP-2310Background
• AOP-4090Background
• AOP-4383Background
• STANAG 2310Background
• STANAG 4172Background
• STANAG 4383Background
• STANAG 4509Background
• STANAG 4820Background
• AOP-02Background
• ISO 9001Background
• STANAG 4297Background
• AOP-15Background
• AOP-48Background