Cast works just fine in the SKS and acuracy can be quite good.
There is the Lee Mold already mentionned that was designed for the SKS, but I am not aware of any commercial manufacture of it.
There's just no market. 99% of SKS shooters are only interested in cheap milsurp ammo, or the non-existent cheap non-corrosive. On top of that, brass is very scarce.