bgjohn, there are a lot of powders suitable for a specific purpose that aren't published, and if you can make one powder work for two cartridges, it sometimes makes things more convenient. Sometimes it's just fun to experiment, if you can be reasonably sure it can be done safely.
Of course a new gun is ALWAYS nice, but sometimes the budget only allows for an new can of powder, and sometimes not even that, so you got to try what you've got.