I got the cartridge adaptors from /www.e-gunparts.com. Sach cartridge adaptors. These can be re-used indefinitely and are of quality steel and are around $20. As far as the 7.62x39 loads, I am loading 19.5 gr of BLC-2 powder under a 155 gr Lee lead bullet that I cast. The 160 grain bullet they sell a mold for also work good and gets the same load. You will need to use a magnum primer with these loads, as this stuff is a bit finicky to light without the mag primer.
I was just shooting it today, and was shooting 5 shot groups @ 50 yds that a thumbnail could cover. No kidding. The load is about 1500 fps and I think I am going to use it for coyotes, as the max shot is 125-150 yards. the Lee program shows that I should sight in at about 3" high to be dead on at 150, while retaining about 600 ft lbs of energy. More than enough for a coyote.
I have had my best luck with Lapua brass in these, but you may need to experiment.