They are short, stuby cartridges, designed by Dr. Lou Palmissano and Ferris Pindell, a benchrest gunsmith, thus the designation PPC (Palmissano Pindell Cartridge). They derive from an old Russian case, and are about 30 years old or so. They, especially the 6PPC, are the mainstays of current benchrest shooters. Both are inherently accurate and seem to surpass everything else in terms of accuracy. They make fantastic varmint cartridges as well. Somedy I'd like to get a Cooper rifle chambered in 6PPC. Sako and a couple others chamber for it. Best wishes.
Cal - Montreal