You're probably thinking of the M134 'Minigun', which is capable of firing at a rate of 6000 rounds per minute.
One or more mounted machine guns is a "nest."
The aircraft mounted machine gun was at first simply a ground machine mounted for a gunner to fire. All sides in WW1 used it. The first successful machine gun fired by a pilot was the Lewis machine gun on a special mounting attached to the top wing, allowing the gun to fire over the propellor.
What type of solider... there are several. You would seem to be referring to a machine gun, mounted on a tripod. Aside from machine gun teams in infantry units, they'll be used by several other personnel.. helicopter crewmen, military police.. even cooks may be assigned them.
Yes and no. Stand by for clarification. There was no AA artillery developed until after the war, but standard rifle bullets were sufficient to bring down most WW1 aircraft. Machine guns were mounted on a tripod which was specially made for AA so it could be angled high. The tripods were available in insufficient numbers, so wagons were turned on their sides and a machine gun on a standard tripod was mounted on one of the wheels.
There is no 25mm handgun. That is the size of an automatic cannon that is mounted on an armored vehicle.
it affected it by gas.
from what I have seen, War Machine has a shoulder mounted Gatling gun, a shoulder mounted rocket launcher, a machine gun on each wrist and repulsors (the repulsors are on the video game, I am not sure about the movie)
Yes
to assualt the ground from an airplane with machine guns or cannons mounted on the airplane.
Aircraft mounted machine guns & cannon mostly.
They mounted two 37mm automatic cannons.
Machine guns and autocannons were mounted on the aircraft which the Japanese used in their attack of Pearl Harbour.