FWIW,
Dr. Sharps from the T/C list just streched a frame with a Lazzeroni round and VV offers a replacement barrel in any chambering in exchange for your VVCG Lazzeroni barrel. Not sure what the details are for the replacement barrel, but if they are doing this, then IMO anything larger than a Win mag case is too much for the Encore.
Don Bower and JD Jones both use 308 case head dia.'s for there wildcats. IMO, they both push the Contender and Encore as far as they can safely.