I use A-Zoom snap caps and it happens with my Stoeger and SKB occasionally especially once the snap caps get old and the flange beat up a little. Never has happened with any real shells. Don't worry about it.
Stumpman of KandT Guns in Arkansas does one of the finest action jobs on this type of pistols. He's my brother but I wouldn't say it if'n it wasn't true. He's redone several of mine that were pretty good to start with but were noticeably better afterwards. And he's quick!
Check the recess in the barrel that the extractor goes into. Had one that wasn't quite deep enough and it bent the extractor a tiny bit. Broke a couple but not anymore.