When I first got into shooting, (Mid 70's) I shot a ton of Thunder Bolts.
They were cheap and consistent, never had any leading issues.
About 5 years ago I picked up a few hundred rounds because they were on sale.
After twenty rounds or so the barrels (single action revolver and MKII Ruger)were so leaded up that you couldn't see the rifling and accuracy went from groups to "patterns".
I still have about 800 rounds on a shelf in a closet.