Huh. OK. Had to ask.
<scratches head>
We're into an area I've not dealt with. I think you need to figure out two things: did Ruger change the chamber spec between the OM and NM, and is there anything peculiar about that Cor-bon load?
I'd ask around at
http://rugerforum.com under "revolvers" next. More likely to get somebody who knows about that gun. Or at:
http://singleactions.proboards.com/index.cgi?board=sas
John Linebaugh would know but he had a mild heart attack recently, he's doing OK but I doubt he's answering EMail right now.