The 22 PPC was developed in 1974 by Dr. Louis Palmisano and Ferris Pindell, primarily as a benchrest cartridge. Although originally a wildcat, Sako of Finland introduced commercial rifles and ammunition late in 1987. Norma followed suit on 1993 with loaded ammunition. The cartridge is based on the 220 Russian case which is a necked down version of the 7.62x39mm Soviet military cartridge. The Wichita Engineering and Supply Co. made the first rifles for both the 22 PPC and 6mm PPC cartridges. Many custom rifles have been turned out in this caliber. In 1993 Ruger announced their No. 1V and M77 varmint rifles in this caliber.
The originators altered the 220 Russian case by giving it a 10% body taper and a 30% shoulder angle, as well as expanding the the neck to accept the standard .224" diameter bullet used in the U.S. The cartridge cases are made in Finland by Sako and in Sweden by Norma and use Small Rifle primers. Although the 22 PPC is a short rather stubby case only 1.51" long, it nevertheless develops ballistics superior to some larger, longer cartridges such as the 222 and the 223 Remington. The 52 grain bullet can be pushed out of the muzzle at over 3500 fps, and this definitely places the 22 PPC in the varmint and small game class. A 1 in 14 inch twist has become pretty much standard for these rifles although 1 in 12 inch twist sometimes be found."
very accurate cartridge, The 6ppc is the more famous brother cartridge and has won too many benchrest comps to count.
google it and read about its development, some pretty interesting stuff