Various weapons are very often exposed in movies nowadays. Here are legendary Russian machine guns having their own history ever shown in the Soviet (and not only) movies.
1. Maxim heavy machine gun model 1910. It was a first self-powered machine gun with water cooling of the barrel. Gun produced after 1940 were upgraded in such a way that coolant circuit could be loaded not only with water but with snow or ice. This gun could provide only automatic fire so it was extremely effective against infantry.
2. Degtyaryov hand-held infantry machine gun was used by the Soviet Army starting from the year 1927. It was one the few weapon models developed solely in the Soviet Union but not changed or modernized western samples. It appeared to be rather fail-safe and easy in use and maintenance and for this reason was widely used till the end of the World War 2. In its combat characteristics Degtyaryov's gun excelled similar foreign analogs of that times.