"Handloader's Manual of Cartridge conversions" says 220 Russian or 220 Swift cases can be used but it's an awful lot of work (trimming, annealing, cutting new extractor groove, etc.).
Hornady factory loads steel cases with SST bullets. I would think it would be quite easy to buy loaded non-corrosive 7.62x39, pull the steel core bullets and replace them with standard jacketed 7.62x39 bullets (Hornady makes 123 gr. FMJs, SPs and SSTs). You could reuse the powder and sell the steel core bullets to defray your cost. However, it's mostly a moot exercise. SKSs, 858s & AKs (when we could shoot them) throw the brass everywhere & beat the hell out of the cases. Unless you have a 7.62 bolt gun you would be better off just selling the die & putting the money towards more ammo.