Resurrecting an older thread, I know.
Giving some consideration to reboring a 660, 243 Win (not the original 20" bbl) to 338 Federal. Been talking to Mark Brown, at Brown Precision and he still inlets for the 600/660. Thought about 358 Win, but I already have on in a Ruger 77 tang safety.
Just me, but Iād do that all day long. While maybe not the more perfect set up, it could be very damned good. With a Brown on it, it might be a complete bush hunters dream.