  This article describes a method and results for direct high-speed
measurements of rifle primer blast waves employing a high-speed pressure
transducer located at the muzzle to record the blast pressure wave produced by
primer ignition. Our key findings are: 1) Most of the primer models tested show
5-12% standard deviation in the magnitudes of their peak pressure. 2) For most
primer types tested, peak pressure magnitudes are well correlated with measured
primer masses so that significant reductions in standard deviation are expected
to result from sorting primers by mass. 3) A range of peak pressures from below
200 psi to above 500 psi is available in different primer types.
