I tried like hell to form belts on 270s trying to form 240 weatherby brass.... but my success wasn't what I had hoped. I got warned early in the game, not to anneal the case head while trying to do this... If you have time and patience, why not give it a try? Hopefully you can learn something and tell us how to do it. Prices of weatherby brass in 240 make trying worthwhile!!
regards,
Graycg