The 22 Cheetah was developed by Jim Carmichel, shooting editor of Outdoor Life magazine and Fred Huntington of RCBS fame. It appears to have originated in the late 1970's. The cartridge is essentially a full length Remington 308 BR case, with a smaller primer pocket, necked down to 22 caliber, but with the shoulder moved forward. What you end up with is a variation of the 308 Winchester necked down to 22, but using a special match case. This is not exactly new because there are in existence several slightly different versions made by necking the 243 Winchester case down, and these date back to the early 1960's. However, the 22 Cheetah is an original with regard to the 308 BR case and its smaller rifle primer pocket.

The major difference between the 22 Cheetah and its predecessors are the use of the lighter, more uniform BR case, blown out 40 degree shoulder angle and short neck. In other words, the case has been designed to benchrest specifications. It also has a greater powder capacity than any of the older versions. There are actually two case types, the MKI with a 40 degree shoulder angle and the MKII with the original 28 degree shoulder. The 22 Cheetah is somewhat more powerful than the 220 Swift, but ballistics were measured from a 27 inch barrel. The cartridge has proven to be superbly accurate and a very effective 300 yard varmint cartridge. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.