It actually doesn't make one whit of difference what your shooting. Remington, Colt, Reproductions, Percussion ....... Nada. Reducing the sight radius magnifies any sighting error. The guns themselves are no more or less accurate. If you lock a 7 1/2 inch barrel gun in a Ransom Rest, and a 4 3/4 inch gun right next to it, you won't be able to tell which gun shoots which group, provided the ammunition has been optimized to each specific gun. The accuracy out of the Ransom Rest becomes entirely dependent on the shooter.
There are miles and miles of variables when judging accuracy. Grip, Grip strength, Trigger position, Trigger pull, Sight Picture add finiteum.
Where was I going ........... Oh Yea .. I remember
The length of barrel only makes a difference to the shooter. What ever the shooter is most comfortable with will work the best for that shooter. Personally, I think any barrel longer than 3 1/2 inches is wasted steel. That's just me. So ..... if it feels good in YOUR hand, it's right for YOU. Even if the barrel is too long