Okay, here's an update on my Son's Ruger: Yes, it had been field-stripped and cleaned and lubed under my direction (this ain't my first rodeo) but I appreciate the reminders. The snap-caps were used to give him some training with the UpLULA loader I got him, he also used them in simulated loading, chambering and re-chambering of the pistol. They were Lyman A-Zoom snap-caps, a brand I have used for years that has a reputation for quality. The problem occured with both snap-caps and American Eagle 9mm hardball rounds that he loaded into the clips and ran manually through the chambering sequence. This morning I inspected both magazines and while using a digital-caliper gauge to determine variences between the domestic and the foreign sourced mags, I noticed that the Italian unit had a smaller gap between the feed lips than the American-made mag. Really close inspection revealed a slight burring of the metal at the curve of the left feeder lp; a burring that seemed to mean that all the necessary metal had not been removed by the press during the manufacture of that part. I worked it a bit with a small file until the width was the same as the US-made unit.
At the range the Ruger ran with both magazines without incident. My son was pleased with the gun and it's ease of use. He especially appreciated the laser since he has some vision limitations (no, he isn't the "blind-guy with a gun!" kind of limitations) and it helped with targeting. We both have a problem seeing front sights; him due to his eye problems, mine because the sights on my 1911 are little and black (soon to be remedied!).
Thank you all for your suggestions and I'm glad the problem wasn't more serious. I thinking that somebody in Italy had a little too much 'grappa' for lunch and didn't watch the magazine stamper closely enough!