I like this thread, so let me break out the BIG GUYNS to save it.
I present to you, the Maxim Gun, because
>A Mutiny resulted.
>I never shall forget the way
>That Blood upon this awful day
>Preserved us all from death.
>He stood upon a little mound,
>Cast his lethargic eyes around,
>And said beneath his breath :
>Whatever happens we have got
>The Maxim Gun, and they have not.
>He marked them in their rude advance,
>He hushed their rebel cheers ;
>With one extremely vulgar glance
>He broke the Mutineers.
>(I have a picture in my book
>Of how he quelled them with a look.)
>We shot and hanged a few, and then
>The rest became devoted men.
-Joseph Hilaire Pierre René Belloc (The Modern Traveler 1898)
It was the first ever recoil operated machine gun, a design so timeless and effective that it was used from 1883 until the '60s. Chambered in many different calibers throughout the ages, the actual mechanism is simple, the recoil pushes back the breech, which then is guided downwards, where it picks up the next cartridge and moved back into fireing position. All this comes in a water cooled package of roughly 500rpm, available in most calibers eventually. A weapon so effective so lacking in competition, that even the German Army, which was probably on the edge of weapons development in early WWI adopted it, or rather ripped it off.