NATO EPVAT testing

NATO EPVAT testing is one of the three recognized classes of procedures used in the world to control the safety and quality of firearms ammunition.

Beside this, there are also the Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (C.I.P.) class of procedures and the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) class of procedures.

EPVAT Testing is described in unclassified documents by NATO, more precisely by the AC/225 Army Armaments Group (NAAG).

EPVAT is an abbreviation for "Electronic Pressure Velocity and Action Time". With Action Time the (short amount of) time required between the ignition of the primer and the projectile leaving the barrel is meant. This is a comprehensive procedure for testing ammunition using state-of-the-art instruments and computers. The procedure itself is described in NATO document AC/225 (Com. III/SC.1)D/200.

Unlike the C.I.P. procedures aiming only at the user's safety, the NATO procedures for ammunition testing also includes comprehensive functional quality testing in relation with the intended use. That is, not only the soldier's safety is looked at, but also his capacity to incapacitate the enemy. As a result, for every ammunition order by NATO, a complete acceptance approval on both safety and functionality is performed by both NATO and the relevant ammunition manufacturers in a contradictory fashion.

For this, a highly accurate and indisputable protocol has been defined by NATO experts using a system of reference cartridges.

The civilian organisations C.I.P. and SAAMI use less comprehensive test procedures than NATO, but NATO test centres have the advantage that only a few chamberings are in military use. The C.I.P. and SAAMI proof houses must be capable of testing hundreds of different chamberings requiring lots of different test barrels, etc..

In this system, the ammunition manufacturers, in close cooperation with NATO, have set aside a batch (also termed "lot") of ammunition they consider to be of very good quality and representative of ammunition that should be delivered to the armies in the next following years. This batch is maintained at approved NATO test centres and distributed to the manufacturers involved. When a new batch (lot) is delivered, a set of 20 reference cartridges are fired to see how they behave with the local equipment and with the current atmospheric conditions. Results are then compared to the reference values as maintained by the NATO and correctors (delta values) are computed. Then, the current batch (lot) of ammunition is fired and the correctors are applied on the measured value giving a result "comparable" to the reference itself.

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