I was able to recover some of my bullets today after the snow melted. My 158swc from my .357mag were smooth and shiny. there were tiny rifling marks on the very base but no where else. Even the tumble lube grooves were gone. The bullet was a Lee Tumble Lube 158SWC. They are sized at .359in. Could my load be to hot. My chrony is not back from repairs yet. The BHN of my bullets id 24. Any suggestions?

24 bhn?
thats harder than my 223 at 2750 fps.
just try air cooling.

Any chance of posting pictures? BHN of 24 sounds rather hard. I have had gas cutting with my harder 44mag bullets in which the gas cut the bullets in between the rifling impressions. Softer alloy solved that problem. At the moment, for rifle loads I use scrap lead pipe with a little plumbers solder added and a little copper dissolved in. That makes quite a soft but tough alloy that stays together when fired into fine sand at rifle velocities - not magnum velocity, just moderate 303 Brit velocity.

This one started out at 208gr and ended up being 199gr.