WAS AS THINKNG THAT AS WELL.
There is one more way to convert the larger bolt face to a small rimless cartridge head.... Leave the face alone and simply mod the extractor (as I have mentioned before for the 7.62x39mm to 5.56mm change.
The modified extractor not only grabs the smaller diameter rimless brass but it also shoves it sideways slightly upon extraction into the ejector. No need to mod the ejector either.
NEED TO GET ON THAT SITE MORE SOME REALLY TALENTED PEOPLE THERE.
I have a thread at WG where I'm doing one in 8mm mauser. I did tack weld a reducer ring into the bolt face. I know folks are gonna say thats a no-no, but I can garantee I didnt get it hot enough to draw the temper of the bolt head. Flame on!