I've come across a Model 19 that has a problem which makes it inoperable. The cylinder rotates with extreme difficulty. If I swing the cylinder out and pull the thumb latch back, the hammer can be cocked and released as normal. However with the cylinder locked into the frame, it is impossible to cock the hammer as the cylinder will not rotate. I suspected a bent center pin so I disassembled the cylinder assembly and sure enough when I mounted the pin in my lathe it showed it was bent perhaps .06" out at the end. Careful tapping on the pin with a rawhide mallet I was able to get it to spin true but after reassembly, the problem persists. Could it be that the crane is bent? So I made a stud that fits inside the crane (without the cylinder present) which has a small end duplicating the center pin. This stud aligns perfectly with the hole in the frame and can be moved by the thumb latch so it seems that the crane is in good order. With the cylinder in place this revolver has zero endshake and I wonder if that is the problem - it fits to tight to revolve. I have cleaned under the extractor and there are no endshake shims present. What else can I look at? Thanks for any helpful comments!

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Gazz

I am assuming the cylinder spins freely when the cylinder is open. If so, I have had two problems that caused this, there may be others!

The yoke tube is too long--could be from a repair or too many shims, when closed it pushes the extractor too far back into the frame.

The gas ring is vibrating forward. I had this happen with two model 27s in a short time frame. Never had it happen before or since. (If this is the case, I would be sorely tempted to send the gun back to the factory to refit a gas ring.)

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Richard Gillespie
FBINA 102

Since we can't lay hands on the revolver, pure speculation follows:


Check to see that the rear of the barrel extension is not rubbing on the front of the cylinder. Deposition of shooting debris on the front of the cylinder face can cause contact, and interfere/stop proper rotation. If the barrel is in contact here, there will be rub marks on the front cylinder face.

The yoke could be out of alignment. You'll need an alignment gauge to check that the center pin is not binding in the breechface cavity.

Confirm that the cylinder assembly is not binding on the front locking lug. This can happen when when one of the components is damaged, improperly fit, the extractor rod is too long, or has too much run out. (not straight)

Is there any change in terms of fitment and function of the cylinder assembly when the yoke screw is removed from the sideplate? The yoke may be binding on the screw. (damage to the yoke button, yoke screw, or wrong screw used)


Carter (aka: "old coot")

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Ret. LE, FA Instr, S&W Armorer

Thanks for the replies!
There is no built up stuff on the cylinder face - the revolver is exceptionally clean and I can see the gap between the barrel and cylinder which looks to be about.010" by my calibrated eye. As I noted in my post, I made a tool that fits inside the crane (or yoke - my terminology may be wrong) when the cylinder is removed from it. This tool is a sliding fit and when the crane or yoke is closed, I can take a piece of stiff wire and push this tool into the corresponding hole in the revolver frame where the thumb latch can push it back out. This leads me to believe that these parts are not bent. The fact that there is absolutely no end shake makes me wonder if that is the problem and that the whole assembly is just to tight to turn but then wonder how did it get this way?

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Gazz

Actually, with use, the rear gauge and the end shake that is built into the revolver at the factory should increase. Can you check the rear gauge with a feeler gauge and see what the reading is?

If the cylinder is recessed, the gauge should be between .012" - .018". If the cylinder is not recessed, the rear headspace should be .060" - .068". Clean and wipe down, then measure between the rear of the cylinder and the breechface just under the top strap.

Have you disassembled and flushed out the cylinder assembly, including the yoke? Perhaps a piece of debris has found its way into the assembly and is causing it to bind. Metal fibers from cleaning brushes can be .005" in diameter, or larger, and can easily cause this condition. Just another possibility for you to consider.

Carter

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Ret. LE, FA Instr, S&W Armorer

Interesting one. I’m anxious to see the fix

Definitely loosen the yoke retention screw and see if it reduces the binding.

When I shot the Combat Law Enforcment Course Model 19's had just come out and were real popular. Many shooters shot .357 mags. The early 19's had cylinders that were bored to close and did not hold the mag. power. I sent at least 4 back to the Factory, including mine for repairs, because the cylinders were expanded, and the cylinder could not rotate. At that time they did what ever to make it right. Mine was many years later, and charged me $200.00 dollars, I had not choice.

Try the gunsmith's trouble shooting method..........
Remove everything from the cylinder and yoke assembly.
Put only the ejector in the cylinder and put the cylinder on the joke and snap it into the frame.
See if the assembly snaps cleanly and easily into the frame.
See if the cylinder will rotate freely in the frame.
Gauge the barrel-cylinder gap.
Gauge for cylinder end shake......it needs to have at least slight end shake to operate.

If everything is good, start putting the other parts in one at a time until the problem appears.

With the cylinder assembly out, closely inspect the cylinder and ejector for any burrs or deformation.
Inspect the cylinder bushing on the front, and the ejector seat in the rear.
Inspect the frame around the barrel and the breech face for burrs or grit.
Inspect the cylinder latch pin for over-length into the breech face. (Pin too long).
Inspect the pawl (hand) for jamming on the ejector.
Check for bolt timing to insure it's dropping out of engagement with the cylinder locking notch and not locking the cylinder in place.

Even if you cleaned it, use a brass toothbrush to liberally scrub the under side of the ejector and it's seat in the rear of the cylinder.
Small particles of grit can get embedded in the steel and prevent the ejector from seating fully.
This grit can be almost impossible to see.

As mentioned above, check the locking bolt timing. It sounds like it's not dropping before the hand is trying to turn the cylinder.

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Randy
SWCA #2468 SWHF #346

I would clean out the center hole in the cylinder with solvent. It sure sounds like the cylinder is binding on the yoke tube.

With the yoke off mount the cylinder on it without the center pin and press it forward and see how it turns, It should only have a very slight amount of drag, Is the front of your gas ring pressing against the yoke? There should be a bit of clearance. It is possible your gas ring got moved forward a bit somehow I guess. With the center pin out and no ejector star, place it on the yoke and in the gun and place a business card under it to defeat the cylinder lock, does the cylinder turn easily when held in alignment? If so place the star in it and do the same thing. If it binds at that point it is a zero end shake problem or your gas ring is slammed against the yoke for some reason. If some one replace the cylinder or star it could also be a rear gauge problem as suggested earlier,

Be great to now the history of the gun, any parts been changed, when did problem start?

Another thought. Even if there is no debris under star does it close up completely tight to cylinder? Maybe a alignment pin got burred or bent a bit

Thanks for all the advice! Not sure what the problem is and since I did mess with the center pin I ordered a new one form GPC. Unfortunately it was different that the one in the revolver, a 19-3 and the shoulder thing is a different location. I had bought one of the imported barrel-less K frames from one of the distributors a couple years ago as I thought I had a 2" barrel in my stash and I did, but the wrong 2" barrel. I made that into a 4" revolver and it works fine so I took the crane or yoke from the 19 and put the .38 cylinder on it and put it in the Model 10-7 import. It works fine. If I put the .38 cylinder into the 19 with the 19 crane or yoke (pardon me for not know what the correct name is for the part) it also works. So it seems that the cylinder may be the issue. Gonna have to dig throught the parts pile to see if there is a .357 cylinder in there.

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Gazz

I have seen one time, and one time only, in 50 years where the extractor rod shaft had somehow become partially loose from the extractor star, allowing the boss in the middle of the extractor star to end up just below the surface of the ratchets, causing the ratchets to become the bearing surface in contact with the recoil shield, rather than the boss; this caused a condition similar to what you are describing. I'm guessing the extractor star was brazed(?) (not sure how the factory attaches the star to the shaft) and somehow became damaged or moved. This was on a Model 13.


Boggled my mind, took forever to diagnose; had to put in a new extractor assembly.

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RJ
SWCA# 2279, SWHF# 709

Any chance the problem is a hand or a ratchet?