75mm (3 inch) cannon you may have seen in a WW2 movie bouncing around behind a Jeep. We haven't made them since 1949 or so, but they're still out there. Most are used now for Salute Guns or avalanche control.
I didn't realize until I read the Tech Manual that they are called Pack guns because they are loaded up on a pack animal and head out over the mountains.
It is such a beautifully simple weapon, has about three moving parts in the breech mech. You can disassemble it, roll the parts around in the mud, reassemble and still hit what you aim at.
To me it's the VW Beetle of artillery! 
I can't wait.
Dan
