Bryan is not correct. There was some Czech production with a mild steel core, and the Soviets produced some during the last couple of years of significant production. However, all Polish, Hungarian, Yugoslav, Bulgarian, Romanian, North Korean, and pre-1990s Chinese, as well as most Czech and Russian 7.62 Tokarev ammo was made with lead cores.
If you subtract the Soviet and Chinese surplus that is not importable for other reasons, there should be more surplus out there, but who knows.......we may have gotten it all.