Russians generally don't need to do that; Russia includes eleven time zones and gigantic military-related manufacturing capabilities and they do not need to buy anything from anybody else to produce weapons. They can produce them as they need them.
Buying…and selling….weapons with other nations forms the basis of strategic partnerships. I think we are seeing this between Iran and Russia, which is buying or in joint production of Iranian drones. Which are proving effective in the war at a low cost.
Iran of course buying Russian fighters. Etc etc …havent tracked it all
Also between Russia and China.