i had 3 shells in the gun and it cycled properly once fired, but wouldnt fire until I released the trigger each time. i completely disassembled the trigger mechanism and there was no dirt or debris. All parts seemed to be in good condition and springs looked good. I'm totally stumped? when I pull the trigger the catching mechanism (on top and towards stock) holds onto the hammer, then when I release the trigger, that mechanism releases the hammer and it fires. ?????????