The Russian army already seems to of shopped around so they already had things like the Vickers machine gun and Lewis Gun. Make sure you have these liberally supplied around the army, perhaps add the Canon de 75 to your arsenal as well.
In 1914 the Russian Army had 76mm M1902 gun which was comparable or slightly superior to French M1897 75mm cannon. For machine gun there was the M1910 machine gun, a Maxim gun, and for a LMG there was the Madsen LMG, the first there actually was.
The Russian problems were not in their equipment for either Navy or Army which was, when available, comparatively well made and in many ways often innovative. They simply had too large army (not to speak of their navy!) for Russian economy.