Most of my revolvers shoot best with water dropped WW metal at 22 BHN but for super tight groups I add tin and antimony to WW's. That gets them around 25 BHN.
I need some expansion with my 45-70 BFR because the velocity is too high so I went to 50-50 WW and pure, oven hardened to 20 BHN. These MUST use a gas check from my gun or groups are sad. They are accurate but I get a flier with every group, sometimes two. They do leave the bore clean but I do not get any leading with any boolit anyway.
Now the .44, .45 and .475 do not need any expansion as long as the boolit has a nice meplat like a WLN or WFN. They kill just fine with a very hard boolit.
The .475 is great and if a deer runs it does not know where it is going and will smash into trees and brush piles and will drop in sight fast. My velocity with the 420 gr is 1329 fps and that range seems to be the best with hard lead. If you load much higher then 1400 fps you do need to bring in some expansion or you will just drill a hole in deer.
Whitworth and I hunt together and we kind of stack up deer like cord wood. I had to quit with six last season because I could not give away any more meat and I hate to butcher. We do a necropsy on them to see what each boolit does and it has been a huge learning experience.
We both can only say that the .475 is a fantastic caliber, destroying internals with almost no meat damage.
Here is what a hard boolit does.