Like I said, Jim got that rig from Cliff Labounty, and Cliff rebored many, many DRs with it for Paul Roberts. I've handled a bunch of them and can tell you that everything from .010" to .047" increases were common, and .055" certainly was not. Aside from a few .303s rebored to 9.3X74R, I've never seen another taken up as much as .055". A minimum of .055" would essentially mean that doubles can't be rebored as almost none would have enough remaining wall thickness to survive proof and, thus, be safe.

For example. Aside from the clunks, most decent quality doubles rifles have a min wall thickness at the muzzle of under .100", some considerably less. A .303 built with .100" min wall thickness would thus have a muzzle diameter of .511". Taking it up .055" to .366" for a 9.3 would result in a min wall of .0725". As a friend of mine expresses it - "Cat shit a monkey!". Even if it passed proof, that's razor thin. No thanks. Keep in mind that most doubles don't quite have .100" min wall to begin with.

You either didn't understand what Jim said, or he's having problems that Cliff certainly did not. Think about it. Your .303 rebored to .358 is an increase of .047", not .055". I personally know of another, probably one of the last that Cliff did, that was a .470 to .500, an increase of .036". If Jim really is having such problems, I guess DR rebores will have to go to Europe.