Why was the machine gun so effective in World War I?
Because generals throughout most of WW1 failed to figure out battlefield tactics that allowed for success against machine guns. They kept sending waves and waves of men to attack opposing trenches defended by machine guns, and that played right into the strengths of the machine gun and barbed wire defense system.It wasn't until late in the war, when the Germans adopted Stormtrooper tactics, that a tactical counter was developed that allowed specially trained troops to attack machine gun positions with a reasonable chance of success, without incurring excessive casualties. Basically, small and fast infantry groups utilizing fire and maneuver and rapid rushes from cover and concealment to cover and concealment to approach and silence machine guns. The basic infantry tactics utilized to this day.
How many bullets per minute can a world war one machine gun fire?
The Germans had a machine gun that shot 750 rounds per minute.
Different Between British and German Machine Guns in WW1?
Very little difference in heavy machine guns. Both essentially made water-cooled Maxim Guns under licence. The difference comes in how they were used. Germany fought much of the war defensively which meant their weapons could be well dug in and sited to create arcs of fire across their front. While the British also created defensive positions, as part of the side which was more attacking the machine gun proved cumbersome to use as infantry support. This was resolved by the use of light machine guns like the Lewis.