Ok were to start....
Ah yes A nordonfelt gun is a stationary machinegun with 12 barrels
It is fired by using a lever it should overheat also
Yes there should be unlimited ammo for the gun
Also for effects i would like the bullets to have tracers like the Repeater gun add-on
Due to it being a stationery machinegun it should be spawn on a vehicle spawn
For more info :
http://en.wikipedia.org/wiki/Nordenfelt_gun