[mrcvs]

In the following thread, Gain Twist is mentioned:

http://www.coltforum.com/forums/colt-percussion-revolvers/73691-1860-question.html

Can forum members post clear examples (photos) of this? What model(s) were produced with gain twist. Obviously, the 1860, but any others? 1849, 1851, 1861? How about Colt Walkers and Patersons?

Are there any reproduction Colt Percussion revolvers out there that utilize this? If not, and if fairly commonplace in the 'real deals' (of course, depending on your responses), is it a fairly reliable way to determine, at the very least, if a barrel is original or a reproduction?

 

[spacecoast1]

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.

 

[BigG]

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?

 

[bearcat6]

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

 

[mrcvs]

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

 

[JohnnyP]

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

 

[BigG]

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

Thanks much. The bullet is just coasting after it leaves the bore. Makes sense.

 

[mrcvs]

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

Does anyone out there know the answer to this question?

 

[BigG]

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.

 

[steg]

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

 

[mrcvs]

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...

 

[spacecoast1]

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

Sounds like the answer then is No, at least not for pinning down a 1st gen gun. However a lack of GT rifling is a definite negative indicator.

 

[Boge]

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

 

[BigG]

I checked a couple Ubertis and they have standard rifling.

 

[rayb]

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

 

[elhombreconnonombre]

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

 

[Oyeboten]

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'.

 

[spacecoast1]

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.

 

[steg]

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).

 

[Boge]

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).

It's more complicated than that, but 2nd & 3rd Gen. are not gain twist. Mine aren't. Look again and measure.