Under the Soviet Union, private ownership of firearms was extremely restricted, but Russia has been gradually changing that policy.
Since 2007, gun ownership is up from 8.9 to 12.3 guns per 100 persons in 2017. That is still a small fraction of gun ownership numbers for the US.
At the same time, the homicide rate has dropped from 17.8 to 6.9 homicides per 100,000 persons in 2016. For reference, the US homicide rate was 5.3 in 2016.
One change is that Russian gun laws were amended to allow owning handguns for self defense starting in 2014:
Looks like more guns in the hands of the right people results in lower homicide rates.
At the same time deaths in mass shootings have increased:
From 2010 to 2019, the number of deaths in mass shootings has increase to 161, from 89 for the decade earlier. List of mass shootings in Russia - Wikipedia
The total number of homicides fell from about 270,000 to about 120,000. For every additional death in mass shootings there has been a reduction of 2000 deaths from homicide in general.
More guns appears to increase the number of mass shootings, but number of homicides is way down. Does concentrating on reducing deaths in mass shootings risk increasing the number of homicides?