I saw and learned from the same thread. Here's a shot of my (real) 1860's barrel from the breech end. As you hopefully can see, the rifling is almost straight to start and then the twist kicks in about 1/3 of the way down the barrel. Sorry for the crud inside, I haven't done a lot to seriously clean it yet.

My 1849 Pocket and my 1862 Police are the same way. I don't have an 1851 Navy (yet) but would wager the originals are gain twisted as well.

I also checked my Remington New Model Army and it's a little harder to tell (looking from the muzzle), but the twist may also relax a bit near the breech.

 

My question is technical: If the twist starts out slow and gains as the projectile flies does it keep speeding up twist the farther the bullet flies? My guess is "yes." How would this be measured?

 

The moment the bullet leaves the barrel there are no longer any forces acting on it to increase velocity (and rotational speed), and velocity immediately starts to decrease. With the bullet decreasing in velocity it will retain the same amount of rotation it had as when it left the barrel, but won't gain any rotational speed. Finally the momentum/velocity of the bullet will slow down to the point that it is no longer rotating fast enough to remain stabilized.





Moonclip

 

My 1851 Navy has gain twist rifling, it was made in 1860.

 

So, is this a reliable way to differentiate an original from a fake/reproduction?

 

Does anyone out there know the answer to this question?

 

I don't know the answer but I just checked my 31 caliber Model 1849 Pocket and it has the same gain twist as illustrated above for the 1860 Army. It starts out almost straight and twists at the far end of its run.

 

I just checked both a 2nd and 3rd gen. Colt M1860 Army from my collection. Both have gain twist rifling.

 

How about your Colt Walker? Much thanks in advance...

 

Uberti has never used gain twist rifling. You may want to look again.

 

You are correct, but, although both 2nd and 3rd gen Colt percussion revolvers were made from rough Uberti castings, they were machine finished, including the bore and rifling of the barrels, in the U.S. by the sub-contractor ( Lou Imperato).

 

I checked a couple Ubertis and they have standard rifling.

 

My 3rd Generation "Trapper" barrels (both barrels) do not appear to have gain twist rifling. The barrels are both serial numbered with the same serial number; I "assume" it was late manufacture, maybe toward the end when they were using up parts. Given that is hard to tell with the shorter barrels, the rifling shows no visual evidence of a twist change.
rayb

 

Interestingly, my 1970s made Armi San Marco Walkers appear to have gain twist rifling.

 

Interesting!

So...at least some of the reproductions appear to have Gain Twist.

Eliminating one of the key deficits which may otherwise allow a fast determination of a 'fake' or 'rendition'.

 

So far all of the Colt percussion revolvers appear to have G.T., so a lack of it would be an easy way to rule out some imposters.

 

So some folks say 2nd and 3rd Gen. Colt percussion revolvers have gain twist rifling, and some say they don't.

Perhaps some of the 2nd and 3rd Gen revolvers have gain twist and some of them don't.

Does anybody know?

Regards

 

My M1860 Army also has Gain Twist rifling in the barrel.

 

Here some pics using daylight.

 

I had known about gain twist as a kid in the 1930s but it took the 1980s to be meaningful to me. I had done a few good trades with a dealer & knew him well enuf to know he tended to be crafty. This time he sent me a respectable looking 3rd Dragoon offered for a trade. Checking it over, no problem, fine bore -- finally dawned on me 'not gain twist' & I sent it back. His attitude was someone playing with the big boys oughta know the rules ----->

 

I checked my 2nd Gen F-Series 1851 Navy and 2nd Gen C-Series 3rd Model Dragoon and they do not have gain twist. I have a Pietta 1858 Remington "Shooter's Model" and it does have gain twist. The pictures by Victrix illustrate gain twist very well.