Something else odd I ran across - A nickel-plated U 43 headstamped military .30-'06 case. At one time, maybe 40 years ago, I had a few such cases, and reloaded them back then. I do not remember where I got them. I just recently discovered one of those old empty cases. Nickeling is sort of dull, not shiny like what you see on new Winchester factory ammunition. I resized it, which was tough to do, as it took a lot of force to get it into the FL sizing die. So why would there ever have been any nickeled U-headstamped cases?
I’ll add a little more information - the case is definitely brass - non-magnetic, and I trimmed the neck length so the brassy color can be seen at the case mouth. I think the plating is nickel, but cannot be certain it is. It just looks like nickel to me. This case has been reloaded an unknown number of times, so the plating may not appear now as it once was.