Model 19-3 won't function in SA

[bookmanwv]

I have a model 19 that all of the sudden won't cock the hammer to fire the gun in single action. It works just fine in double action.
I have searched any key words I can think of and can't find any guidance on what may be the issue.
Taking the side plate off the gun looks perfectly normal based on schematics.
Has anyone had this issue before? I have owned the gun for 20 years and never had an issue.
Thanks All.

 

[Muss Muggins]

Four possibles, and the only one that will be readily apparent to a novice is the first one:

Bent hammer spur (you dropped it, and the spur is bent so that it blocks the hammer from going all the way back)

worn cocking notch on the hammer (use related)

worn trigger bevel (use related)

the bolt doesn't go forward when you close the cylinder (damaged extractor rod, damaged center pin spring, or the yoke is misaligned)

it is also possible that there could be a bunch of crud around the bolt and the cylinder latch that keeps the bolt from going forward. This is the easiest to fix.

Replacing the hammer fixes the first two, replacing the trigger fixes the third, and there are four possible fixes to the fourth. All require a gunsmith who knows his/her way around the internals with the proper tools.

 

[gutterman]

Clearances are very tight and it sounds like the hammer may possibly be hanging up on something. Might take a look to make sure the cylinder latch under the hammer is not causing the problem. Also make sure hammer itself is fully seated although you stated it works well in DA. Other than that its just look till you find.

 

[Alk8944]

First check the strain screw. If it is too loose the hammer will bind on the end of the too-straight spring before it is fully cocked. The bent hammer spur is a good possibility too. If it got progressively loose, and the trigger pull got lighter and lighter progressively then it could be either the hammer or trigger that need replacement. If you tried a home trigger job and tried stoning the hammer notch this would explain it too.

The bolt IS NOT the problem. It will prevent the gun from cocking in either mode if it isn't being pushed back far enough when the cylinder is closed.

 

[Muss Muggins]

The bolt IS NOT the problem. It will prevent the gun from cocking in either mode if it isn't being pushed back far enough when the cylinder is closed.

The information I provided is a direct quote from the Trouble-Shooting Charts in my Smith and Wesson Revolver Armorer's manual, which I received at the Smith & Wesson factory in Springfield while attending the revolver armorer's course. Perhaps there is a difference in terminology, but the bolt in the wrong position can cause multiple issues, including failure of the hammer to lock back in single action. The OP is free to believe it or not, as are you.

 

[Mike McLellan]

All in favor of the problem being a worn trigger bevel. let out the old rebel yell. "YEEEEEEE HAWWWWWW!!!!". Or not.

 

[bookmanwv]

Thanks for the info. Gives me several options to research.

 

[Neumann]

I've experienced a loose tension screw, resulting in the same problem. The mainspring binds and won't allow the hammer to be fully cocked. The sear never engages and the hammer can't be pulled back to the end of its slot.

If the SA sear is damaged, it will still click but not hold. A damaged lock will cause problems with both DA and SA. Bent hammer? You'd know if you'd dropped the revolver, and the spur would be hitting the frame.

 

[Alk8944]

The information I provided is a direct quote from the Trouble-Shooting Charts in my Smith and Wesson Revolver Armorer's manual, which I received at the Smith & Wesson factory in Springfield while attending the revolver armorer's course. Perhaps there is a difference in terminology, but the bolt in the wrong position can cause multiple issues, including failure of the hammer to lock back in single action. The OP is free to believe it or not, as are you.

Makes no difference what you quoted, do you have 50+ years experience working on S&W revolvers? The bolt (I assume you really do know what the bolt is) moves BACK when the cylinder is closed, and is pushed FORWARD to unlock the revolvers cylinder. If the bolt does not move BACK far enough the inter-lock portion will prevent the hammer from being pulled to the rear more than about 1/16". As long as the bolt is back far enough to allow the hammer to be cocked it WILL NOT prevent cocking, or firing in either single or double-action.

As stated before, there are several reasons why the gun would not cock for single-action, but the bolt is NOT one of them.

 

[walrus100upd]

model 19 problem

I have a model 19 that all of the sudden won't cock the hammer to fire the gun in single action. It works just fine in double action.
I have searched any key words I can think of and can't find any guidance on what may be the issue.
Taking the side plate off the gun looks perfectly normal based on schematics.
Has anyone had this issue before? I have owned the gun for 20 years and never had an issue.
Thanks All.

To clarify what is happening with your gun, do you mean that when you place your thumb on the hammer spur and attempt to cock it , the hammer travel stops near the beginning of movement, as if being blocked by something ? Or do you mean that the hammer goes all the way back and wont engage to stay in the full cock position ?
Ted

 

[walter o]

Did you change grips ? I put a set of foreign made grips on a model 15 with had a target hammer The new grips blocked the hammer from going back far enough to work in single action .Gun still worked fine in D.A.It had me baffled for a second or two