I posted this in a thread where it was relevant but since it may be of broader interest, posted again here with a bit of dialog. Gain Twist is the only name I ever heard of it - where the rate of twist (turns per inch) in rifling increases thru the bore, from very little at the entry (or cylinder) to the muzzle where it is much greater.
Gain twist is present in all the perc Colt types I have been able to check, Dragoon, 1849 Pocket, 1851 Navy & 1860 Army.
As far as I know, none of the repro makers have done gain twist rifling, which is one of my check items. I was offered a Dragoon in trade & being suspicious about the dealer, I checked and found the barrel with constant rifling, meaning the barrel was a modern repro antiqued to look right. NO deal.
Gain twist is present in all the perc Colt types I have been able to check, Dragoon, 1849 Pocket, 1851 Navy & 1860 Army.
As far as I know, none of the repro makers have done gain twist rifling, which is one of my check items. I was offered a Dragoon in trade & being suspicious about the dealer, I checked and found the barrel with constant rifling, meaning the barrel was a modern repro antiqued to look right. NO deal.
