458 Lott conversion?
I'm buying a Steyr-Mannlicher S/T in 458 Win. I'm wondering what kind of trouble/expense would it be to have the chamber modified to accept 458 Lott. That way it would still fire 458 Win, but could also launch 500 grain pills with about 1000 fp extra ME, should the need for extra power (or just the need for speed) arise. On the other hand, this is a high dollar gun (for me) and I don't want to screw it up. Any thoughts, advice, etc? I assume the 0.3" longer head space would deteriorate accuracy with the Win round, but nobody uses such a gun for paper punching.