Yes, and they're still serving a very essential role in the battlefield.
Yes
Yes
What do you mean? It is used because it still does its job.
Yes, machine guns were used in WW2.
Auto ordnance used to but i do not know if they still do.
ding dings rock
machine guns and rifles
Did you want to know what calibers were used in machine guns or perhaps what cartridges are for machine guns only.
Efficiency
it is an ancient counting machine used in China, it is still in use today
it used machine guns
Used extensively.
All of them.
Every country