I was using 9mm shot shells in my S&W s/auto and when I pulled the trigger the seated shell in the chamber fired correctly BUT-the next shell in the magazine fired as well (2 shells fired in 1 trigger pull); has anyone else heard of this? My neigbor asked why I was shooting a shotgun in the backyard, it was so loud. Could this have happened due to the very light metal/composite make-up of the ammo casing? I'm taking the pistol to a gunsmith to have it completely checked for stress fractures or other damage I can't easily see. The retailer was indifferent when I asked about this --referring me to the manufacturer and/or S&W.