For what it is worth, as a former NMLRA competition pistol shooter (25 and 50 yd. matches) using flintlock, caplock and the Ruger Old Army revolver, I was interested in the best twist rate. Most of the other available revolvers, the Colt replicas for instance, had a twist rate around 1:32 as I recall (check an older Dixie Gun Works catalog's descriptions), but I found a friend who could measure the twist rate of an original Remington 1858 Army revolver. It was gain twist, ending in 1:16 twist at the muzzle. That takes skill to measure!
So the 1:16 twist of the Ruger Old Army doubtless was chosen wisely, based on the above knowledge. With the low powder charges used in competition to decrease both fouling and recoil, a distinctly faster twist rate all the more gives the Ruger Old Army an accuracy advantage, I believe. You will find the Master Class ML pistol shooters using Ruger Old Army revolvers, not the other available caplock revolvers. (The sights are better, too.)
May I suggest respectfully that the Ruger Old Army is no longer made and the price keeps going up. There are a lot of other caplock revolvers that could have their barrel shortened, or bought that way, and thus leave the prized Ruger Old Army as is.
Aloha, Ka'imiloa