I just purchased a Ruger New Model Blackhawk Bisley in 45 Colt. The model number is 0407. It is the Turnbull finished gun so the serial number starts with TBB. Is this a Large or medium frame revolver? I do not yet have the revolver in my hands as it is being shipped. Also, I really want to get a 45ACP cylinder and not sure if I can buy a used one from an Old Model Blackhawk as I see some used ones for sale. Mike