NotClauswitz would have a Lewis Gun. An interesting choice, invented by Isaac Newton Lewis in 1911, the Lewis was never adopted by the U.S. military, but was primarily used by the British in WWI and again in WWII. Among it's other history, it was the first machine gun to be deployed on an aircraft.
Made by Savage Arms in the U.S. and Birmingham Small Arms in England, it came in three flavors, .303 British, 8mm Mauser, and 30.06 Springfield. There aren't many available as transferable, the one I found with a price sold in 2010 for a little over $13,000.
I did find a news story about a man in (formerly) Great Britain that wanted one bad enough that he took one he had acquired, got it working, and then sold it to a man who owned a WWI De Havilland II airplane. As you can imagine, both the police and the press got the vapors, but amazingly enough, the trial ended in an acquittal.
But enough of the history for now, here, to Pachelbel's Canon is the Lewis gun in action.