Save your money on pure silver rounds. All that is needed is a silver alloy. Course it MIGHT take a round or two more, but you can have more rounds for the same amount of money. I would go HOT 357 or larger. Shotgun loaded with buck or slugs would work really nice. Course your big bore brass cased rounds will do wonders as well.

Now if we could just get Dan to make us a silver alloyed blade...