  This article describes a method and results for direct high-speed
measurements of firearm primer blast waves employing a high-speed pressure
transducer located at the muzzle to record the blast pressure wave produced by
primer ignition. Key findings are: 1) Most of the lead styphnate based primer
models tested show 5.2-11.3% standard deviation in the magnitudes of their peak
pressure. 2) In contrast, lead-free diazodinitrophenol (DDNP) based primers had
standard deviations of the peak blast pressure of 8.2-25.0%. 3) Combined with
smaller blast waves, these large variations in peak blast pressure of
DDNP-based primers led to delayed ignition and failure to fire in brief field
tests.
