The images show what I believe to be a Kynoch 455 Mark I Webley cartridge I possess. I am curious about the degree of primer crimping used for this cartridge, being ringed and stabbed. Why would it require such firm crimping? Or is it just the way it is and no real reason?
As an example, in HWS Volume 1 (revised), page 112, they discuss a Cal. .30M 1906 cartridge that used stab and ringed primer crimping in order to prevent the primer blowing out when the cartridge was fired in the Marlin aircraft machine gun because the bolt provided little support the cartridge head.