I don't know a lot about this cartridge. It is also known as the.7.92×57mm Mauser. SAAMI calls it the 8mm Mauser or 8X57mm. C.I.P. calls it the 8 × 57 IS. It is a rimless bottle necked cartridge. The 8mm Mauser cartridge was adopted by the German Military in the early 1900's. They used it through both World Wars. Harbour Arms has them because you requested them! Two snap caps per package.