Well 1st of all it sounds odd, loud but odd. Actually that's all that happened. I was out with some of the boys today shooting beer cans & such, just happily blasting away, when Tom's Colt 1911 did not sound quite right. After he emptied the mag he came over to me with a badly ruptured case and asked 'what happened'?? A quick glance at the back of the case gave away the news that he had cycled a .40 through a mag with the 45s. I replied " do you do this often??" (with an implied 'you moron') life goes on Wanna kill these ads? We can help!