The filming of the assault on the Winter Palace required 11,000 extras, and the lighting needs left the rest of the city blacked out.
Sergei Eisenstein had to remove most of the footage featuring Lev Trotskiy. The re-editing caused the film to be reduced to a little over three quarters of its intended length.
More people were injured reproducing the storming of the Winter Palace than were hurt in the Bolsheviks' actual takeover of the building. '(Source: Young Stalin by Simon Sebag Montefiore).
Bolshevik revolutionary Vladimir Antonov-Ovseenko, who personally led the storming of the Winter Palace in October 1917, played himself in the film's re-creation of that event (and clearly enjoyed doing so). We see him lead a charge with a revolver in his hand, order the palace guard to stand down, and sign the decree ending Russia's Provisional Government. A former ally of Lev Trotskiy, Antonov-Ovseenko was arrested in 1937 and executed the following year, during Stalin's political purges.