A couple of my dies have a really light haze of rust on them and was wondering if these could be tumbled in my tumbler to remove it? Its on the inside of my competition bullet seating die. I removed the dial portion so as not to damage any of the numbers.

my approach would be to polish the inside with a sacrifice bore brush wraped with a larger cleaning patch charged with Flitz polishing compound. operate this combo in a cordless drill for at least 2 minutes-plus up to 4 additional minutes, clean up, inspect and give her a test run.

my guess is they will perform better than new after polishing with the Flitz.

have you tried vaporust?

I'd just use some gun oil on a piece of fine steel wool and a dowel...

I know I'm low tech, but I can tell ya, having the problem on some dies given to me, that method easily solved the problem...

Saved some really nasty ones by tumbling in stainless media.

If any of the dies have micrometer heads I wouldn't tumble them for fear of damaging those ultra-fine threads. If it were a sizing die I would chalk it up to a learning experience and replace them. Seating dies I would at least try polishing them out.