My ridiculous hypothesis of it being a low penetration weapon designed for time travelers to leave no trace when traveling to the 1942-1957 time period when the M3 was still in use was a bit of a stretch.
However Having a weapon loaded with non penetration rounds for home defence is the American Way, despite a fully automatic SMG being a comically poor choice.
Either way, whatever slug he was using would be hilariously underpowered for anything other than tearing paper.
Having a target round of any sort loaded with the gun sitting on the rack seems odd and somehow an American thing.
My ridiculous hypothesis of it being a low penetration weapon designed for time travelers to leave no trace when traveling to the 1942-1957 time period when the M3 was still in use was a bit of a stretch.
However Having a weapon loaded with non penetration rounds for home defence is the American Way, despite a fully automatic SMG being a comically poor choice.