I know several here own doubles in the .577 BPE family. I am thinking of rebarreling a Ruger No. 1 to .577 3-inch BPE to be shot primarily with black and cast. My Pedersoli Kodiak .58 has 1:48 twist, as did a Snider that passed through my hands. Believe Krieger offers a 1:30. Don't know if that would be too fast for a 550-600-grain bullet at 1700, but I am sure it would be fine with a smokeless plinking load.
Any advice most appreciated.