Ben, you're going to have fun with that project. I did something similar with a 10" .357 T/C 20+ years ago, and wrote it up for HHI (The Sixgunner). I don't know that I will be able to post the original article (that was done on a very old Mac), but I will retrieve the pertinent loading data and share it with you. The long throat means you can seat the heavyweights out long, and get some surprising velocitites. As I recall, I was getting 1400+ fps with 250+ grain cast bullets, and excellent accuracy.