Your completely wrong on this point. The danger is not that Russia will run out of ammunition, the danger is the Russia - like the US - will run out of enemies in Ukraine (which is happening right now).

Russia's economy, unlike the US, is running on a war footing and really cranking out ammo. Millions of shells. They have something like 7.5% of their economy now supporting the war. What happens when they finally defeat Ukraine?

My fear is that to keep the economy cranking along, Russia, just like the US will want to keep the "good times rolling" by supplying weapons to the global south. Maybe also Georgia or Transnistria.

The difference to the US is that it is the Russian state+oligarchs rather than just the US oligarchs, but to world peace that won't make a difference. World conflict will increase, which is bad for humanity.