you really believe they can't make ball bearings? a thing people were making almost since time began
As Rilot says ball bearings are a fairly new thing in metal working as they required a lot of technology to back them up.
High precision metal working to the tolerances expected from modern engineering is not easy and requires very high levels of skill in the operators and increasingly complex machinery with an ever increasing support structure, and that costs a lot of money.
Given Russia was meant to be making every part of certain things important to national security/independence "internally" so they could be independent of the rest of the world for things like tanks and tractors, and it turned out they were quietly buying in their "Russian" tractors from Europa in parts then assembling them on a production line and pocketing the very significant difference in cost it's not surprising they don't have a lot of that supposed capacity (one of the reasons you make a point of "producing everything needed" for something like a tractor in country is that a lot of those skills and tech are used in things like tank engines...).
And even if you've got the ability to turn the metal blanks into what you want, it doesn't mean you have the ability to reliably produce the quality of the metal blanks as that in itself requires you have steelworks that are capable of producing specific types of steel and do it reliably and consistently and the steel needed for modern precision heavy duty bearings is a very specific and I believe hard to make version (IIRC one of the ways a lot of western steelworks have survived the influx of "cheap Chinese" steel was to specifically specialise in the stuff the Chinese either don't make in bulk, or have trouble producing reliably).
China as a mundane yet extreme example make most of the worlds ball point pens (and have done so for decades), but IIRC it was only about 5 years ago they actually cracked making the bearings and nibs needed so they didn't have to import them from the likes of Japan and Sweden (one of the Chinese companies finally decided to invest in the R&D and it took several years).
Even just getting the metal right for a precision ball bearing is a highly complex task and requires very high QC at a well maintained steelworks, something that is very costly to do compared to making generally low quality steel, buying in the good stuff to pass QC then pocketing the difference (which has been the Russian way for a very long time now due to corruption*).
There are actually quite good reasons why a lot of "precision" stuff tends to be made either in large quantities by a very small number of companies, or in smaller quantities by companies that might well receive government assistance/preferential treatment for contracts to ensure a country maintains that capacity. Unfortunately for the Russian military, much of the money that was meant to maintain the ability of Russia to do that sort of precision work reliably seems to have gone into the pockets of criminals who happened to be friends with the people awarding the contracts who were more than happy to turn a blind eye to it (or rather get distracted by the shiny stuff in the suitcase).
*Even during the 30's and 40's it was common for production figures and reports to be falsified at every stage from the factory floor up, but at least back in those days there was a reason other than greed for a lot of it (if the choice is between lying about how well your factory has done and exile to Siberia or execution as a traitor you might well lie and hope for the best).
