Model 19 misfires

[rpg0123]

I bought a pristine model 19-5 that shoots great, but I'm having some occasional misfires with it. Today was my second range trip with it and I noticed that on the misfires the dimple from the firing pin was more shallow than it was for the good fires. I have checked the mainspring screw and it is fully tightened with the head flush to the metal on the front butte. Any other suggestions?

 

[n4zov]

The gun might need a thorough cleaning since it is possible gunk or a heavy lube is slowing down the hammer fall. Also the factory mainspring may have been replaced with a reduced power spring or the original spring may have been ground down. Finally, if the ammunition you are using is handloaded it might be the cause. At least these are some areas to start your trouble shooting.

 

[rpg0123]

I guess I'll have a smithy take a look at it tomorrow. I'm kinda wanting an opinion here from somebody knowledgeable about repair costs and such. If the gun is otherwise in great shape and I just bought it, will I be able to have the problem taken care of without a lot of money/hassle or should I just send the gun back? I would prefer to keep the gun if I can repair it with a reasonable cost and have a really good chance of getting the misfires under control. The gun looks brand new and has unbelievable accuracy.

 

[bgrafsr]

Have you checked for cylinder end shake? If there is some, it may be enough that when the hammer drops it pushes the cylinder forward enough to cause the hammer nose to make a light strike on the primer.

 

[rpg0123]

Cylinder seems just as tight as a new revolver. I did notice comparing it to a newer revolver last night that it looked like the firing pin might not come out quite as far into the cylinder, but this is a completely different revolver, so that may be apples and oranges. But the firing pin tip is nicely rounded, doesn't appear to be worn.

 

[pownal55]

primers not fully seated will cause that problem.

 

[tac803]

I had a batch of misfires from my pre model 15, and a model 36. The ammo was the culprit. It was factory "re-manufactured" fodder, and wasn't worth the box it was sitting in.

 

[user]

The most common replacement hammer spring is made by Wolfe; if it's one of theirs, it will have a ridge down the middle, having the same effect as a variable rate spring. They're available both in standard and reduced power. The standard factory spring is flat.

I recently had a similar problem which I figured out was due to the relatively "harder" primers in the target ammo I was using along with crud buildup in the passageway the firing pin slides through. (I do use reduced power Wolff springs, btw.)

 

[rpg0123]

I'm pretty sure it isn't the ammo. I used multiple types and all decent. I really knew I had a problem today when it misfired with a Hornady custom round. I probably had about 2 misfires out of 55 shots today. The spring is flat, so I guess it's factory. Would it be best to take it to a local gunsmith for a tune-up or send it to S&W? I just want to do whatever it takes to get it in tip-top shape because I plan on using it regularly.

 

[m1gunner]

Check to make sure the spring screw wasn't cut down, and is still full length.

 

[rpg0123]

It looks full length I guess. It looks like a clean end on the screw, not altered or anything.

 

[rpg0123]

Shot 50 rounds through today single action - not a single misfire. I'm guessing this means previous owner did lighten up the mainspring somehow? I'm also guessing that if I have any sense I'll leave it alone and just shoot it single action? It has a great blue finish, a hair trigger, and superb accuracy. Why spend money to tighten the trigger and risk having the finish harmed or losing accuracy just to fire it DA instead of SA? Opinions?

 

[texagun]

I'm guessing this means previous owner did lighten up the mainspring somehow?.... It has a great blue finish, a hair trigger, and superb accuracy.

The fact that you say it has a "hair trigger" is a tip-off that the mainspring has been tampered with. I would replace it. Who would want a gun that wasn't reliable in both single and double action???

 

[rpg0123]

It is in with the gunsmith right now. He thought the trigger felt a bit light and suggested that we drop a new spring in it and go from there.

 

[rpg0123]

I finally got this gun back from the smith, and the trigger is much stiffer. I'll have to try it out at the range tomorrow.

 

[rpg0123]

The model 19 is now fixed. A new spring was put in and it works like a charm.