Back in the 80's I used to shoot cast bullets in a 30-06 I had, used them on jackrabbits just for the fun of it. They had gas checks on them and were cast straight up tire weights. I've still got the mold and sizer/lube die around here somewhere. I have absolutely no idea what load I used though, it's been so long ago, but they shot pretty good and leading wasn't a problem. I need to check my old Lyman manual and see if I have the load in there.
I should dig that stuff up and cast some bullets to try in the 300 BLK.!