[Slamfire]

That is hard to tell from a fuzzy picture. All rimfire ammunition is coated in a wax and the bullets are externally lubricated. If you tumble the stuff be aware it is rimfire ammo and who knows if one will go off in the tumbler, and then, you need to lube the bullet again.

The risk of a burst case is real depending on the depth of corrosion. I would never fire one with corrosion on the case head or rim because a case rupture in those areas will cause a mess in any action. Always wear shooting glasses and expect brass particles to come out.

I would say shooting this stuff is a calculated risk and something could go wrong.