There is some semantic creep in this thread, although perhaps with good reason (not the reason you think). Congress got into the act now and then. In some branches of the service, automatic rifles got called "machine rifles," which follows the logic of "machine pistol" and "machine carbine." And some tanks were called "combat cars" because some people weren't supposed to have tanks. So they got combat cars instead.
Anyone want to talk about "personal defense weapons?"
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.