[quoteThe heavy rim on the .475 No 2 looks like a good design feature for a DG gun. Why is this not more popular?

I never seem to see an older gun for sale in this loading, and it doesn't seem like any of the new manufacturers such as Heym, Searcy, Merkel, etc. make guns for that cartridge. ]

jagermeister, the biggest reason for the lack of rifles in this cartridge, is not because it isn't a good cartridge, because it is one of the best. However, the brass is so large it is hard to draw, without a lot of loss in the process, makeing the brass very expensive, and hard to find a reliable sourse for it! This is a very good case to make some of the older Black powder cases from, because it is heavy, it can handle a lot of pressure without problem. I have some brand new HDS brass made by the OLD BELL brass, some fine brass. I make cases for the old 500/450#1 Express Black powder, and Nitro for black rifles.
I agree the heavy rim, is a plus that most NE cartridges could benifite from, and the heavy brass walls can contain a lot more pressure, takeing some of the pressure off old double rifle actions, increasing their lifespans.