.45 Long Colt.
Then get some Winchester PDX ammo and some Glaser grays and blues and some Ultramax.
The Taurus Judge Vs. The Box O' Truth
http://www.theboxotruth.com/docs/bot41.htm
Lessons learned:
1. Jack bought this pistol for snakes and it looks like a fine tool for that job.
2. Birdshot, in any gauge, is for little birds.
3. Buckshot out of a .410 does not penetrate enough to be an effective personal defense load.
4. The rifled slug was also a disappointment and did not have enough weight or power or penetration to be effective as a defense load.
5. The .45 Long Colt loads had plenty of penetration and would be the preferred defense load for this pistol.