My HL Pershing is finally back up and running (and firing!!!), but after testing it to make sure that it was all OK and fully functional, the next night I was so eager to get it charged and start driving it through the house (it was dark outside!), that I only realised that I hadn't removed the plug from the end of the barrel as I fired the gun..... Fired it again without the plug and the next shot just plopped comically out of the end of the barrel! Fortunately, it has since been firing fine (and taking chunks out of the paintwork!)