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'épreuve des armes à feu portatives (C.I.P.)

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

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

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.

Then, samples of the current batch (lot) of ammunition are fired and the correctors are applied on the measured value giving a result "comparable" to the reference itself.

Each weapon will be individually tested, from an ammunition lot that produces a minimum corrected mean chamber pressure in accordance with the table below:[1] The above proof round pressure requirements for the 9 mm and 12.7 mm rounds established by the British Ministry of Defence are higher than the current (2008) C.I.P.

This slight error is not always well mastered and this causes a lot of discussion about the filter order, cutoff frequency and its type (Bessel or Butterworth).