In discussing the inability of my Father's B-24 gunners being able to hit a German Auircraft, he pointed out that they were trained with shotguns while riding in the back of a truck. Targets would go past as they were driven along and shot at the targets, which were also moving. Just a SWAG gere, but single shot guns would seem to me to be very dangerous, and giving them more than one shot at a time would be a disaster. JUST A THOUGHT.