That is a real gem. When I was a kid, probably late 50's, the Watervliet Arsenal used to have an open house every summer. They would put on a demonstration of the latest hardware that was going to the military. I remember a three man team on the stage with M1A1's(M14) demonstrating the semi and full auto capabilities, by firing those rifle off in a grand fashion. They also had an M2 adapted to run off compressed gas, with the firing mechanism attached to a trigger set a bit away from it. I also remember that you could not have slapped the grin off this kids face after getting a chance to fire it! I doubt that tis sort of event happens any more, and that is a shame.