Being unable to make the range to fire the new Custom 1911 I just received. I thought I'd cycle the action to hand feed a few rounds by slingshotting the slide. Big disapointment!! A large number of rounds nose dived and jammed from all 4 "tuned" McCormick mags supplied with the pistol. Is there a common cause for nose diving rounds? I've had several .45's in which I used the McCormick mags and they functioned very well. Makes me wonder about the Smith "tuning" the mags. My last custom (a Springfield worked over by Clarke) would feed empty hulls and never a burp in any way. Any suggestions and comments appreciated.