Model 19 misfiring

[wheat]

I bought a used S&W model 19 a couple weeks ago and it doesn't fire consistently. Some cylinders only 50%.   Hammer nose looks as good as another one.  I'm guessing the main spring?  Have others had similar issues?  Thanks in advance.

[wendigo]

Strain screw tight?

[weiler]

What ammunition are you using? If hand loads what primers?

And noticeable end shake with the cylinder?

I’ve had issues with me 19-5 before but eventually found the culprit was not properly seating CCI 500’s

[needsmostuff]

Dec 10, 2023 17:48:56 GMT -5 wendigo said:

Strain screw tight?

Yeah!!!This ↑↑↑↑↑↑↑
If it appears tight also check if it has been ground down.
Commonly held belief that that is an adjustment screw.
Just taint so.

[wheat]

Screw is tight and does not appear to be ground. Cylinder's tight too. I am using cci primers. I did order the heavier main spring from Wolf. Maybe I should have ordered a strain screw too, just to be sure.

[Encore64]

Do you have feeler gauges? Can you measure the gap between the case and frame?

How deep are the primers dented after firing?

[wilecoyote]

...a spent primer cup between the main spring the nose of the strain screw could do something to stiffen the same main spring, once full tightened...

[wheat]

18/1000 feeler gauge snug fit between cylinder and frame.
Good advice with primer cup trick on screw.
Primers are nicely dented. But I've seen better.
I notice that it gets worse as I shoot it. I live in colder climate, if that would make a difference. It's not that cold +30s.

[Encore64]

.018" is a tremendous gap. Usually about .003-.007" behind the case head.

[bradshaw]

Dec 10, 2023 17:45:56 GMT -5 wheat said:

I bought a used S&W model 19 a couple weeks ago and it doesn't fire consistently. Some cylinders only 50%.   Hammer nose looks as good as another one.  I'm guessing the main spring?  Have others had similar issues?  Thanks in advance.

*****

When misfires (misfire is failure to fire) occurs in a double action revolver, it’s important to specify:

Mode of fire
!) single action
2) double action
3) single & double action

Hammer fall is heavier in single action. The more detail fed into a question, the better the chance of a helpful answer.
David Bradshaw

[AxeHandle]

If you like the action as is... Federal primers may be your best bet. I run CCIs in my magnum stuff but everything else runs Federal.

[wheat]

Misfiring occurs with both single and double action. More often with double action.
My feeler gauge is too wide to get between the top strap and the middle of cylinder. Could be less than what I measured. A different 19 measures 15 at same place.
I appreciate everybody's response. I will continue to trouble shoot so I can shoot.

[needsmostuff]

Dec 11, 2023 8:46:32 GMT -5 wheat said:

My feeler gauge is too wide to get between the top strap and the middle of cylinder.

Nope, wrong place to measure.
Measure at the back of the cyl. between a shell rim and the recoil shield.
Does the cylinder seem to slide much forward and backward?

[jgt]

I would also try cleaning the inside really good and then use a thin coat of lube. I am talking dip a rag in oil and ring it out then wipe the surface to be lubed. Leave no excess. Put it back together and tighten the main spring screw all the way down. If it still misfires, try Federal or Winchester primers. CCIs are known to be harder than the rest. Good luck.

[tj3006]

I Have a model 19, that would misfire in double action.
I was about to send it out for repair when I saw some crud inside the firing pin.
If I had the gun on hand I could describe it better, but I sprayed some oil on the hammer mounted pin and scrubbed it good.
No trouble since.
My 19 is a no dash from 1958. Yours might have whole different set up...tj