Gunshot Residue Deposits on the Gas Pistons of Assault Rifles

Abstract

Abstract A novel technique is presented to determine whether certain assault rifles using gas-cycling have been fired since their last clean-ing. The presence of soot on the head of the gas piston of a weapon allows an examiner to make an estimate of how many times a particular firearm was fired. This is an important observation, as the cleaning of this element is essential to achieve a good operation of the firearm and hence is part of the daily military maintenance. This result is valid for different types of ammunition. The quantity of gun shot residue increases linearly with the number of shots.