Dueling in America lost popularity right after the American Civil War. Dueling in most of Europe went into rapid decline after WWI. It seems wars with high body-counts cause cultures to view the effects of contemporary weapons in a less romantic light. If you want dueling to persist in Russia then you need to keep Russia out of any high body-count wars.
Next, dueling was an activity of the upper class (but not top nobility). It was considered a right of their class and it was used to help defend their position. Even in America, which was more egalitarian than Europe, dueling was an activity of white collar workers; doctors, lawyers, publishers, etc. Peasants and common laborers did not have the right to duel. So this would mean that dueling is very unlikely in a communist Russia.
Dueling also seems more likely in a culture where this upper class feels under threat from the lower classes (lesser nobles losing power through changes in government systems, for example).
How about a shorter and less bloody Russo-Sino War (You also need to keep Russia out of WWI and WWII as much as possible). The government is better able to resist internal rebellions, so the communist revolution does not happen. But there is some sort of revolution where labor and the peasants gain a lot of political power and freedoms. The Russian upper class feels its existence, as a class, is under threat and clings to the tradition of dueling until the present day.