fuhrmann,
When I make 11.15x51R cases from 45-70, or 11.15x60R from 45-90, they do, indeed, expand. In these cases, there is no problem. I turn the rims to .595", instead of .585", so the rim centers the case in the chamber and insures even expansion. This is after reforming the rim to MB type. I had head separations with CIL factory cases that turned out to be balloon head. I also saw 43 Spanish factory case (UMC ca 1912) blow the head out. They turned out to be folded head cases, fired with .080" excess headspace( one barrel thread). Extreme care must be taken with old cases, and the shoulder must mot be set back in hand loading. Dies should be set to just "kiss" the shoulder, instead of the shellholder hitting the die. You are absolutely right to be concerned about this. You are also right that the name of the cartridge doesn't matter if you can make cases and bullets that fit. The Mallmart is not going to have any, anyway.
Mike
