7.62x51 M80 can be converted to .460 rowland, but in a very roundabout and probably unintentional way

Making a .460 Rowland casing requires a .308 casing, but NOT a 7.62x51 casing. You can get around this by disassembling the 7.62, making it into reloaded .308 Winchester, then firing it out of a gun, since reloaded ammunition can’t be disassembled. This creates a .308 casing. I found all this out when I thought I could make some .460 out of my 7.62 stockpile. There’s a bug here, either that the .460 Rowland casing can’t be made from 7.62 casings or that firing rounds reloaded with 7.62 casings returns .308 casings. Maybe both. I’m playing on 0.D stable by the way.