I called Rossi and found out the 44 magnum singleshot rifle is 1:20 twist.
I just picked up one of these off gunbroker that was a 44mag/20ga combo and gave $250 for it total to my dealer.
It seems to shoot well at 100 yards but some my loads need tweaking a bit. Plus I am going to try the rubber washer in the forend trick that will free float the barrel and see what happens.