I guess an update is due:
Despite Mr. Steve Koch at RCBS being a very nice and polite guy the final word is that RCBS will no longer do any custom die work to a customers “unusual” chamber.........so I did not get any die to my chamber. Sad, they were a great company once upon a time. Fred Huntington is spinning in his grave.

At least I was able to get a proper .577/.500 No2 shell holder after much wasted phone time, etc. and I FINALLY got my fired cases returned. RCBS customer service is, as they say, “a cluster FLOP”

Due to work and home life I have not been able to do much of importance with the .500 No2 in quite a long time......
- Mike