All About Primers with the U.S. Army Marksmanship Unit

The effects of different primers on ammunition accuracy is a topic that interests many, but which relatively few can easily test with precision. Most competitive shooters are limited in their access to a 1000-yard range and a quality accuracy-testing facility. Thus, experimentation with primers is often done at shorter ranges, relying heavily on chronograph results to help select primer brands or lots by velocity uniformity and accuracy testing.

Source: Shooting Sports USA