I just had the same problem with my SBE II. Purchased last year and never had a problem.
This past weekend using 2 3/4" Federal Premiums #4's, it jambed 6-8 times catching the shell by the brass flange on the way out. I tooked it back to Cabella's who sent it out to there gunsmith, waiting to hear back.
Another buddy with a SBE has had the same problem.