The sources which claim Russia will run out of X within months have been doing so for over 2 years. There's still no shortage of Russian arms of any sort.
It's like people don't know anything about how absolutely massive the Soviet military-industrial complex was, and how much of it still exists in Russia. I spent over 10 years of my career doing all kinds of fundamental analysis on the economic & manufacturing capabilities of China & its neighbours (CCP numbers are lies, and my employer wanted to know what was really going on), starting from energy & ore extraction and moving all the way up the production ladder.
I did a back of envelope calculation for Russia and it's really not good for the Ukrainians & NATO. Their production capacity is in the same ballpark as what the Russian MoD claims it is, in other words, Russia can completely replace their losses with margin to spare. Russia is far more industrialized than most people think, it actually produces more steel from iron ore than the US and it has more heavy forging presses for stamping out all kinds of parts such as gun barrels, aircraft landing gear, turbine shafts, and parts for more machine tools to speed up production. Thanks to its oil industry, it also has a huge petrochemical industry which produces all the chemicals needed for the explosives used in various weapons. With their natural resources & production capacity they're not going to run low on anything any time soon, and their economy will be just fine unless we can cut them off from China or find a replacement for oil & gas.
Or put it another way. This is just one of the dozens of factories cranking out ammo for the Russians. It's every bit as modern as anything in the Western world and probably cranks out as much ammo by itself as the Scranton plant in the US. These factories are literally everywhere in Russia, but especially in the Urals (thanks, Stalin).