I used to work at a quarry that was used to test artilery back before the start of the war. Anyway due to having this knowledge, the management installed huge electromagnets on the conveyor belts to pick off the projectiles as they came up into the processing departments. I have one of these that is 3 3/4" long and 1 1/2" in diameter. It has a brass driving band and a cap on the rear that will only allow it to be screwed in and not out. It weighs a pound and has the letters "P E & M CC" stamped on the driving band. Any ideas about what I have?