Colt timing issues

[SmithManatee]

I know that Colts with the positive lock design are designed to have the hand applying pressure to the ratchet inorder to make the cylinder hold still for more accurate shots and this causes the hand to wear away quicker causing timing issues. When the mk III series came out they replaced the positive lock design with a transfer bar design and the hand no longer held the cylinder in place so it didn't wear away as fast. Did the hand on Colt double action revolvers before the positive lock hold the cylinder in place and are there any revolvers besides Colt revolvers that do the same thing?

 

[dfariswheel]

An issue with terminology:
The Colt "Positive lock" was an extra hammer block safety added to the Colt design in 1905.
Prior to that, the Colt's had only the hammer rebounding safety.
If dropped the hammer rebound/lock could break, allowing the gun to fire.
The addition of the extra hammer block made it virtually impossible for the gun to fire if dropped or the hammer was struck.

As for the tight lock up of the cylinder when the trigger is pulled, this was known as the Colt "Bank Vault Lock up".
This lock up by the hand pressing on the ejector ratchet was present in the Colt New Navy of 1889.
I'm not sure if the double action Colt Thunderer/Lightning/Rainmaker models of 1877 also locked tightly.

I don't know of any other modern revolver that locks the cylinder tightly when the trigger is pulled.

 

[MCgunner]

It is said that the Colt system requires a lot more hand fitting and I can understand that. It does apparently run the cost of production up. I don't really see the advantage in the system, myself. I do have a Taurus M605 poly back ordered. The literature on it states that it has a clockwise rotating cylinder to facilitate easier reloads. WHAT? I don't quite get that one, either. I never had a problem loading a swing out cylinder no matter which way it rotated. I do think, however, that the 605 Poly, unlike Colts, has a forward lock at the ejector rod like the Smiths. I can see how the Colt system could wear the hand quicker and cause it to go out of time, but in reality, I don't know that this is a problem. Someone else with Colt experience will have to address that one.

 

[Jim K]

What the OP calls the "positive lock" is the result of using a two step hand, and has nothing to do with the use of a transfer bar. In the Colt system, the first step ("finger") of the hand engages one ratchet tooth to start the cylinder moving, while the second step engages the next ratchet tooth to force the cylinder against the cylinder stop during firing. The lockup is solid and was much touted by Colt. But it also has a disadvantage - if the gun is worn, the hand can actually force the cylinder too far, moving it out of alignment.

From a salesman's viewpoint, that "bank vault lockup" was great; as a practical matter, it means little in terms of either functionality or accuracy.

Jim

 

[SmithManatee]

Just to clarify when I was talking about the positive lock I was referring to the hammer block and I did know that the tight cylinder lockup was called a bank vault lockup. However I did not know how accepted the term bank vault lockup was so I didn't use it in order to avoid confusion. I also didn't know if they added the bank vault lockup with the positive lock or if they used it before or if other revolvers used it.