231/HP38 are made by St. Marks - in Florida. PB is made by IMR - in Canada. VV powders are made by Nammo Vihtavuori Oy in Laukaa, Finland. All are carried and resold by Hodgdon in the US. 231/HP38 are double base; PB is single base. The only VV powders which are double are a few of their rifle powders.


Sometimes, the air you 'let in'matters less than the air you 'let out'.