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 is a very fast burning powder for small rifle cases like Hornet or .25-20 and larger pistol cases. Similar in burning rate to Hodgdon H110.
Big Book Catalog, Issue:67, Page:527
Sinclair, Issue:5A, Page:094