I recently purchased my second AMT Hardballer (Irwindale manu.) and although my first (Covina manu.) has been an excellent piece, this one has a few quirks. I had it at the range Thursday and when I would release the slide with an empty mag the hammer would follow about 70% of the time. While firing there was never a problem. I also noticed that, "from the safety notch", the hammer will drop if the trigger is pulled. I inspected the hammer and find that it only has a ledge(?80 series) and no notch like my earlier AMT. There is no firing pin safety in either of these AMT Hardballers so why no notch in the Hammer? Should I replace the hammer? And what do I need to adjust or replace to stop the following problem? The gun has a Wilson Combat FL guide rod and 18.5lb spring, ambi thumb safety, and a 298 grip safety. Do the hammer and sear have to be replaced together? Thanks.