When I got my SP101 .357 Magnum in the early 90's, it would lock up occasionally too. I sent it in to Ruger and they performed some minor deburring. I have never had a problem since. I wouldn't think that the problem that your friend is having is a general problem with the guns in the new caliber. It's basically just putting a new bullet into an existing design. Perhaps, in a rush to get them onto store shelves, a number of them were hurried along the line.
This kind of stuff can happen with any make of gun. I've heard reports that many Sigs have been coming out with some problems too, and I have a S&W 686 that I got in 1985 that was recalled for a firing pin bushing problem that I believe got an officer shot. I still need to send that one in, but I've never had any problem myself.