newer glocks and in fact MOST new guns are made with different manufacturing processes that make them modular. this modularity means that they all undergo some break-in during the first few rounds. You may not have thought you were breaking in a glock before but you were in fact doing so just by shooting. just because you didnt have issues didnt mean it wasnt happening. I seriously doubt there is anything wrong with your gun, just clena it up and lube it then go back to shooting it. this is not a full fledged internet emergency... you had a dud.