looks like a .308 Winchester very close up (camera lens right in front of the cartridge, hence tiny oven in the background) with a hole drilled in it to me… but I guess it could be a .50 cal… it's bigger than the standard .223 that comes out of the most common AR-15, that's for sure…
metal detectors only work on metal objects… not all firearms are metal… it's better to have a person who will shoot back.
lol well, let's get that thing on Total Recall :) I still think an armed person is worth any electronic sensors.