The post 900,000 E can be converted to rimmed case by installing the correct carrier and cartridge guide. I just finished converting a post mil 308 E to 375 Win. This required removal of material from the magazine cavity to accommodate the fatter (forward) cartridge dimensions, but material removal is not required for the 30-30, 303, 25-35 or 22HP. I have not tried a 32-40 or 38-55. I modify 308 carriers to fit the rimmed cases as well, because I have a bunch of them on hand. It does complicate installation of the carrier a bit, but once installed, they work well.
