Question about timing a second cylinder

[awp101]

Let me state up front, I'm fairly mechanically inclined but I've never tried to time a revolver.

I've read about picking up a second cylinder or replacing the missing cylinder for a convertible and the possibility of having to adjust the timing to make it work. Here's my question(s): doesn't that affect the timing for the original cylinder? Or is the amount of adjustment usually so small that any effect on the original cylinder is negligible?

Thanks! :mrgreen:

 

[Hondo44]

People always say that, but in 30 years of swapping cylinders in Ruger SAs, I've never encountered an added cyl. that required re-timing, it's just that rare. Even using Colt cylinders in Ruger mid frames!

But you're theoretically correct, if a 2nd cyl needed timing it would be such a small increment, it would not likely affect the original cyl. Cases in point; look at the tens of thousands of convertibles Ruger makes each year with two cyls that both time correctly in the same gun. It's the Ely Whitney "uniform parts tolerance interchangeability" invention at work. That's not to say it couldn't happen, but it would be a rare exception.

The only fitting typically required on a cyl swap is the over all length because the individual cylinder frames vary due to the hand grinding of the frame castings. It's easier and cheaper to fit the cylinders to the frames than to make all the frames precisely the same size.

Although single actions are a fairly simple action, correctly timing them takes an understanding of the parts interaction. With your mechanical inclination, you'd have no problem learning just by observing the parts as they move. I've never read a manual to learn timing. Guns that aren't working right are good practice too. Adjusting one part can affect the coordination of other parts. And small increments of metal removal on one part can make big differences because of mechanical advantages built into parts design and have large affects on other parts interactions.

For example and very briefly:
The SA cyl pawl is operated by the hammer and the more difficult to understand because it has two 'teeth'. The first starts the cyl rotating. If it's too tall, it tries to turn the cyl before the cyl bolt unlocks from the cyl notch. But the cyl bolt may be at fault and unlocking late because of wear, or malfunction of the hammer plunger that operates it. If top tooth is too short, it doesn't advance the cyl far enough for the 2nd tooth to start turning the ratchet and the cyl stops turning and everything just binds up.

The lower tooth on the pawl eventually takes over to rotate the cyl when the top tooth slips off the cyl rachet as it rotates away from it. If the 2nd tooth is too long, it will rotate the cyl too fast and the bolt will lock the cyl before the hammer reaches full cock, then the hammer can't go far enough back to cock. A too short 2nd tooth won't advance the cyl fast enough and the hammer will reach full cock, and keep going until cyl locks. Ideally the cyl locks in place simultaneously with the trigger sear dropping into the full cock notch.

Hope this is helpful,

 

[awp101]

Jim, it most certainly does! Many thanks! :mrgreen:

One day I really need to sit down with one of my single actions and observe how everything interacts.

 

[Precision32]

Here's my question(s): doesn't that affect the timing for the original cylinder? Or is the amount of adjustment usually so small that any effect on the original cylinder is negligible?

Thanks! :mrgreen:

Depends on which parts you work on to make the gun time. If you make adjustments to the hand (hands), any adjustment will effect both cylinders because the hand is common to both cylinders. If you can make adjustments to the new cylinder to time the gun the original cylinder should run just as it did before, as you have not changed anything.

 

[Hondo44]

The cyl doesn't get adjusted except for length. It's out of tolerance if the pawl doesn't work with it, but works with the original cyl..

 

[rugerguy]

...what they said above and is "spot" on,,,,,, basically you are NOT "retiming" your gun or the 'new' cylinder, you are "fitting" THAT cylinder to the gun, nothing else needs to be changed to the other cylinder , NOR the gun itself................. :wink:

 

[Fox Mike]

I have a stainless Bearcat and a Shopkeeper. Both seem to be OK as far as timing goes however...the Shopkeeper cylinder functions OK in the Bearcat BUT the Bearcat cylinder will not 'lock up' when placed in the Shopkeeper.

 

[Hondo44]

Fox Mike,

Not unusual, has to do with parts and frame dimensional tolerances.

The 2nd tooth on the pawl in the Shopkeeper is a hair too short for the Bearcat cyl. A pawl with a very slightly longer tooth would work for both cylinders.

If you swapped both pawls and/or hammers, or both; both cylinders might work in both guns.

 

[Fox Mike]

Fox Mike,

Not unusual, has to do with parts and frame dimensional tolerances.

The 2nd tooth on the pawl in the Shopkeeper is a hair too short for the Bearcat cyl. A pawl with a very slightly longer tooth would work for both cylinders.

If you swapped both pawls and/or hammers, or both; both cylinders might work in both guns.

The pawl rotates the cylinder into the correct firing position OK. The cylinder latch, however, will not engage the Bearcat cylinder when placed in the Shopkeeper.

 

[Hondo44]

Frank,

In what way does the latch "not engage the cyl" mean?

Latch does not pop up?
Latch won't fit in the cyl notch?
Latch is too low to reach the cyl?

You're not providing enough detail, can you be more specific?

 

[Fox Mike]

Frank,

In what way does the latch "not engage the cyl" mean?

Latch does not pop up?
Latch won't fit in the cyl notch?
Latch is too low to reach the cyl?

You're not providing enough detail, can you be more specific?

Best way I can describe it is...If I cock the hammer RAPIDLY everything locks up OK. I then pull the trigger, it drops normally and at that point the cylinder can then be moved backwards slightly...as if the latch is not fully engaged. Tried it again just before writing this and found that it only happen on two of the cylinders

 

[loaded round]

I've added three conversion cylinders to my Ruger revolvers. A 9mm cylinder to my OM Blackhawk 357, a 45ACP cylinder to my OM Vaquero 45 Colt, and a 44 Spl/44 Mag cylinder to my OM 44-40. Outside of some minor fitting, I never had any type of timing problems with any of these three handguns. Never changed a cylinder on a DA revolver so I can't speak about timing there.

 

[Hondo44]

Best way I can describe it is...If I cock the hammer RAPIDLY everything locks up OK. I then pull the trigger, it drops normally and at that point the cylinder will can then be moved backwards slightly...as if the latch is not fully engaged. Tried it again just before writing this and found that it only happen on two of the cylinders

Frank,

Ok, got it...when the hammer is cocked either slowly or rapidly, the hand is extended to its full height with the lower tooth holding the cyl notch tight against the right side of the cyl latch.

Once the hammer is dropped, the hand retreats all the way down and no longer is pressing the cyl forward in rotation. The left side of the cyl latch engagement with the left side of the cyl notch should then prevent backward cyl rotation.

In your case one of two things is happening:

1. most likely, the cyl latch is not allowed to rise high enough thru its rectangular hole in the bottom of the frame window, to reach to the bottom of the cyl notch.

2. or, the left edge of the cyl notch and/or left edge of the cyl latch are worn and rounded which allows the latch to slip out of the notch and the cyl rotates backwards.

Look for the bright spot worn thru the blue in the bottom of the cyl notches. If there’s no bright spot the latch is not tall enough to reach the bottom and can slip out at the left side of the cyl notch which is shallower than the right side.

The latch must be tall enough to contact the bottom of the cyl notch. If the gun is too new to have a bright spot, to check, use a black Sharpie pen to coat the bottom of the cyl notches. Cycle the action until the cyl has rotated all the way around 1 or 2 times and look for a spot in the ink. If there's no contact footprint in the ink, raise the latch by relieving it's front end top surface under the frame which limits its rise height. The latch must be removed to do this.

If the left edge of latch or notch is rounded, resurface the top of the latch bump so it has sharp crisp corners on both sides. Check latch height again to confirm it’s reaching the bottom of the cyl notch. Note, the Ruger latch must be flat on top from side to side, not angled like a Colt.

Also, if the worn stripe in the cyl notch leade is not in the center, but on the front or rear edge of the leade, the curved shape of the latch is not right. If the front edge of the leade has the wear stripe, the latch is too high in front, or if on the rear edge, the latch curve is too high at the rear. This can be done with latch in the gun. Check by using the Sharpie in the leade.

Let us know what you find,

 

[Fox Mike]

Hondo44: Looked at all the areas you stated and found the problem. The was a very very slight burr on that one cylinder notch. Just a quick look and it really didn't show up. I did a close look and there it was. I simply took a screwdriver and 'cleaned' the notch and now all work the way they were intended to.

 

[Hondo44]

Bravo! I always like a happy ending.