Unfortunately, IMR-4350 is getting hard to find.  I usually get powder at the local Cabelas, and they've been out for almost a year now (or they're always out when I go look).  At Camp Perry during nationals week, the venders that sell powder were all sold out quickly, while there remained a lot of other powders!  Fortunately, there is a sporting goods store not too far from me which only sells shooting stuff... and they had several lbs of the stuff last month so I bought a couple!