AFTE Store - Vickers Hardness Values of Selected 40 S & W Primers

A study was conducted to evaluate the Vickers microhardness of primers from five different brands of 40 S&W unfired cartridges from major manufacturers. Primer hardness is affected by the structure and the composition of the brass used in its manufacture and by the nickel plating if one is used. This study measured the Vickers microhardness and the thickness of the primers. Nickel platings increased the apparent microhardness of the primers. Differences were found in the average microhardness values of the underlying brass of the primers, and these differences were clearly attributable to the different grain sizes of the brass.