AFTE Store - Breechface Recess Marks on Cartridge Cases Discharged from 9mm Walther P99 Series Pistols and their Persistence

This report describes the breechface recess toolmarks noticed on Walther P99 pistols and their persistence. Experiments involving five Walther P99 pistols were conducted in order to determine the occurrence of changes of the marks on the cartridge cases after firing each pistol several hundreds of rounds. Results have shown that the breechface recess toolmarks (among others) retained their characteristics right from the first expended case to the last one. Quite significantly in one case these were the only marks available for characterization of the weapon.