I decided on a Ruger .44 Magnum Super Blackhawk, with the 7" barrel.  Legal for whitetail in my state, you see.  Having neglected to actually check the retail supply, I assumed that the shortage would be primarily the military calibers (9mm Para, .45 ACP, 5.56mm NATO, .308, and 7.62x39mm) with the civilian calibers being readily available.

Experienced wheelgunners are already laughing.  Took me a month to track down 100 rounds of basic .44 Magnum.  Eventually, diligent checking at Wal-Mart (I work nights, what else is open at 5 AM?) landed me another 200.  Over the rest of the summer.  Usually buying the one remaining box of 50 rounds.