Bought a used 930 today and when I tried it out I found that it will not fire repeatedly. I load it chamber a round then fire but then nothing happens when u pull the trigger a second time. I found that I have to put the safety on then back to fire to fire the next round and I have to do that between every shot. It seems like the safety engages after every shot but the saftey switch remains on fire at all times. What do you all think