I had experimented with a 530 gr paper-patched bullet for a little while, had to be seated pretty deep to function. The load data I used was given/copied for me from an older Lyman manual for a 550 gr bullet. It shot fine, the velocity hovered around 1400 fps. I felt this load was safe, I haven't made any more for a while because my wife had a baby and I've been short of time for such a labor-intensive projectile.
Here's the data I was given by ButlerFord45:
Unique 12.0gr@1012fps to 14.0gr@1100fps
2400 20.0gr@1096fps to 26.0gr@1400fps
IMR 4227 23.0gr@1160fps to 28.0gr@1335fps
IMR 4198 26.0gr@1162fps to 32.0gr@1386fps
IMR 3031 34.0gr@1273fps to 39.0gr(compressed)@1442fps
552 Grain Cast w/gas check
Bullet #462560
Accuracy Load:
IMR 4198, 32 gr@1386fps
LYMAN 45th.
Hope this helps, I have always been intrigued by heavy bullets. Load Carefully! jpuke