I installed a timney trigger on a new sendero about a month ago and realized today that when the gun is held upside down or straight up in the air the firing pin is released when the bolt is closed when safety is in fire position (the gun was not loaded when I discovered this). Never releases unintentionally when held in normal positions and the bolt is worked. It can be jarred off by slamming the butt of the gun on the ground but it has to be slammed very hard, hard enough that it doesn't concern me. No unintentional firings either when the gun is pointed straight up, bolt worked, then taken off safe. So what would cause the gun to fire without pulling the trigger only when bolt is worked with safety off and the gun pointed straight up or held upside down?