I got a chance to wring out some more cast bullet loads in 7.62 X 39. I am using a 150 gr RNGC from a Lyman mould. I cast them very hard (near linotype hardness) and quench in water straight out of the mould.
Standard gas check and hard (heated) lube. Thompson Blue angel is my favorite. Lube in back half of the grease grooves. Sized to .310 they should be pretty close to bore diameter.
Winchester cases and large rifle standard primers. Win-748 is my preferred powder for most rifle loads so I gave it a go. For the 123 gr FMJ's I use 27.5 grains so I dropped that down and worked up. I found that 24 grains of 748 gives good accuracy (2 moa) and perfect functioning. 24.5 grains works also w/o leading but is a bit compressed. I don't have the exact OAL but I leave the front 2 grease grooves exposed.
I have not chrono's the load but should be around 2000 fps. It functions and shoots accurately in both my Norinco SKS and Polish AK. Cheap bullets that function perfectly fine, shoot accurately and hit hard. What more could one ask for?