While we generally just cover firearms, this seemed like too cool of a news item to ignore. Umarex, the German company in the same group as Walther responsible for dozens of .22LR trainer designs, also has an air gun division that makes some toys for big boys.
This brings us to their full-auto 1:1 scale metal-framed M3A1 Grease Gun replica that can rip out 1,050 BBs per minute via an open-bolt design until its 60-round mag runs dry.
Better yet, there are no NFA hassles on air guns, so this can (in most states) be shipped right to your door for about $250.