First, I have loaded some warm 300 gr cast bullet loads in my 45 Colt Ruger SA Bisley. I'm getting about 1250 out of a 5.5 " barrel and about 3" groups at 50 yards. The cylinder throats are all about .451. I would like to make this gun a dedicated 300 - 325 gr cast bullet hunting revolver. These groups are ok, but what is possible? I plan on sluggging my bore first to help me pick a good bullet size. I should be shooting 0 to + .001 of groove size, correct? Next, I plan on doing some fire lapping to smooth the throats and bore. Will thiss give me a measureable increase in throat diameter? Also, what should I do next for accuracy? Should I ream the throat? If so, has anyone tried the throat reamer available from Brownells? . . . or should I look at having the gun rethroated? Can I rethroat myself? Wheree can I get the proper setup from for doing this by hand?