I purchased a new G3 21SF this past Friday (3/17) from local dealer. Didn't notice until I got home with it that the serial number on the barrel does not match the serial numbers for the slide and frame. I have several other Glock pistols (all purchased new) and on all of them the barrel serial number matches the slide and frame numbers. I am now worried that maybe my "new" gun isn't new after all. It looks new, but this mismatch of numbers has me upset. Any ideas as to how this could happen with a "new" weapon?