Light Strikes on a S&W Model 19-4

[GypsmJim]

I've owned the gun for 10 years or more and have not had a problem before. When I bought it the PO said it had a "trigger job", and it's evident by its very light trigger pull. However, its also the most accurate S&W I own.

Recently started having light strikes and no fire. Using handloads. Naturally, the first thing I did was check primer seating and that was OK. If I try hitting it a second time, maybe it will fire maybe not. Yesterday it took 4 tries with one round. If it doesn't fire on the second try, its still a light strike. When it finally does fire, the primer strike is normal.

I can go thru several cylinder reloads and it won't happen. Then, it starts again.

The same ammo is 100% OK in another .357 revolver.

Any suggestions appreciated...

 

[Rpg]

Be sure the strain screw is tightened down.

Trigger work often includes backing the strain screw out a bit and can back out further over time.

 

[nachogrande]

WHAT DID THE "TRIGGER JOB" ENTAIL?

If it worked fine for 10 years, it sounds like something has changed. (duh) Start with the simple/easy/cheap stuff first IMO. Look at the (hammer mounted?) firing pin, FP channel clean/clear/lubed?, hammer pathway not gunked up?, springs weakened?, As mentioned above, has the strain screw loosened? still have the original springs?

 

[GypsmJim]

If it worked fine for 10 years, it sounds like something has changed. (duh) Start with the simple/easy/cheap stuff first IMO. Look at the (hammer mounted?) firing pin, FP channel clean/clear/lubed?, hammer pathway not gunked up?, springs weakened?, As mentioned above, has the strain screw loosened? still have the original springs?

All good comments and all have been looked at.

Clean and oiled for sure. Strain screw tight. I don't know if the springs are original, since i bought it used, but I never changed anything. Springs weak? - how do i tell?

 

[Arquebus357]

You really can't tell without gunsmithing equipment. If it was me, I would buy a new hammer spring, install it, and see if that fixes the problem. If it doesn't, I would need to look for another culprit.

 

[Protocall_Design]

In that situation, usually the main thing that changes is endshake. If the cylinder has too much play front to back, (more than .002), then the hammer may have to move the entire cylinder forward before there is anything solid to strike against. Moving the cylinder cushions the blow of the firing pin on the primer.

It could be something else too, we are just guessing without the gun in hand.

 

[ken158]

Most "trigger job" gunsmiths merely cut springs and filed the main spring screw to accomplish their task for unknowing gun owners. Cheap and quick but the end result often ends up where you are now. New springs and screw area a suggestion but someone of knowledge needs to see it.

 

[BC38]

If there is a possibility that the strain screw has been shortened maybe you could try shimming the screw with and empty primer cup over the end of the screw. It would be worth a try, and if it works you can go with that "fix" or get a replacement screw.

 

[1sailor]

I have a M686 that started doing the same thing. A couple of years ago I installed a Wolff ribbed mainspring. Gun never missed a beat until about a month ago. I was going to replace the spring but first tried the old primer with the guts removed trick. since then I've put around 800 to 900 rounds through it with no more issues. Not sure why it started with the light strikes all of a sudden but at least for now the primer trick seems to be working.

 

[David.Hylton]

Any ammo changes or primer changes? I had a 640 that would not consistently fire Hornady ammo, but it would shoot everything else that I tried without issue.

 

[R*E]

Did you clean the cylinders thoroughly so that the rounds are fully seated? If the cylinders have carbon rings, the hammer strikes will push the rounds forward until they are seated.

 

[GypsmJim]

Endshake is not detectable - its tight as a drum.

The strain screw sure looks like it hasn't been touched. I compared it to other Smiths.

The brass is the same, as are the primers, except for maybe a new brick. I only use CCIs.

As a matter of fact, it started after my mid-Winter gun cleaning marathon. I do all my guns in the off season. The cylinders look fine.

Now that i think of it, the only change was the load and the bullets. I used to use 158 SWC lead, but switched to Berry's 158 plated for outdoor use. I guess next time I'll try a box of lead and see what happens...

Thanks for all the help so far...

 

[Tjohns42]

I just had a trigger job done and my local smith had a chart of pull weights that varied by primer brand. CCI was at something like 56oz on .38 special vs Winchester SP at 46oz (these numbers are specific to how he does his action jobs and should only be used as an example in this case). Those are some of the hardest primers you can buy. I would try to check your trigger pull and give your strain screw a nudge to see if that helps. If it started during your off season deep cleans you could've bumped that screw a little and a little is all it takes when you're on the edge with your pull weight.

 

[Protocall_Design]

Bullets won't make any difference in misfires. CCI is the hardest primer to set off. I would take out the mainspring and straighten it out some, then put it back in and try that. It will make the trigger pull a little heavier, but may set off all the primers.

 

[RVRSMITH]

I've owned the gun for 10 years or more and have not had a problem before. When I bought it the PO said it had a "trigger job", and it's evident by its very light trigger pull. However, its also the most accurate S&W I own.

Recently started having light strikes and no fire. Using handloads. Naturally, the first thing I did was check primer seating and that was OK. If I try hitting it a second time, maybe it will fire maybe not. Yesterday it took 4 tries with one round. If it doesn't fire on the second try, its still a light strike. When it finally does fire, the primer strike is normal.

I can go thru several cylinder reloads and it won't happen. Then, it starts again.

The same ammo is 100% OK in another .357 revolver.

Any suggestions appreciated...[/QUOTE
Sounds to me the mainspring is on the verge of not being reliable would be my first guess.

 

[Marshal Kane]

Bullets won't make any difference in misfires. CCI is the hardest primer to set off. I would take out the mainspring and straighten it out some, then put it back in and try that. It will make the trigger pull a little heavier, but may set off all the primers.

I don't think I would want to try straightening out a mainspring. Springs are heat treated to return to a specified shape and once it's changed, can't be changed back. I would suggest installing a new main spring instead.

 

[Protocall_Design]

A properly heat treated spring can be reshaped (slightly) and will hold the new shape. I've done it for 40 years.

 

[jimmyj]

Install a new mainspring and mainspring tension screw

 

[stansdds]

Leaf spring bending, when done carefully and not making huge changes in its shape, can be done. Making significant changes in the spring's shape or repeated re-bending of the spring will weaken it. I'm wondering if in the performance of that trigger job the spring's shape was significantly altered or repeatedly altered to get that light trigger.

 

[Marshal Kane]

A properly heat treated spring can be reshaped (slightly) and will hold the new shape. I've done it for 40 years.

If you've been doing this for 40 years, I'll just have to admit that you're right.