VihtaVuori is a Finnish Powder Company that has been manufacturing powder since the 1920's. VihtaVuori powders are extremely popular with benchrest shooters, High Power shooters, and varmint hunters.
This powder is very close to IMR-4198 in burn rate. Thus, it is ideal for 6mm PPC, 222 Rem., 223 Rem., and other applications where a relatively fast burning rifle propellant is needed. Probably the most popular PPC Benchrest powder used in the world.
Big Book Catalog, Issue:68, Page:544
Sinclair, Issue:5A, Page:094