When it comes to pinfire cartridges, everything is a variation. Though there are thousands and thousands of variations, in this article we will focus on the 80 that came from the White & Munhall reference collection.
Henry P. White & Burton D. Munhall ran a development engineering lab that was founded in 1936. They were acknowledged as the leading private laboratory engaged in small arms and ammunition research and development. The following sales brochure from the company gives a lot of detail on the work that they did.