Hi all, recently my 39-2 started to misfire in single action. Cock the hammer and pull trigger again the round fires and casing ejects. repeat.....

I am not a gunsmith so I hope some of you more knowledgable will have some ideas. Thanks!

Sounds like maybe an accumulation of gunk in the firing pin channel, or weak mainspring, or perhaps grips binding on the mainspring if htey aren't original.

I had that problem with a SIG 210 once. Took out the firringpin and cleaned the Channel and the pin (and spring). Problem solved.

Thanks guys, I will remove the Pachmeyer grips and put some Hoppes #9 to work in the firing pin area. I am definitely not used to FTF on any of my older S&W semis.

That will not work. You need to remove the firing pin and spring to clean the channel.

On my 639 not only was it full of gunk, the spring needed replaced.

It's not hard to do. You need to take care of this the correct way.

BLM

After you clean, lubricate the hammer pin and sear. Slow lock time, due to lack of lubrication, can cause FTF.

Given the age of your 39-2, I'd replace the hammer spring just as a matter of course, as it's inexpensive and easy to do, to eliminate that as a possible cause.

If it's still the original spring, what you're experiencing could be symptomatic of a weak hammer spring, where an otherwise "normal" amount of residue in the firing pin channel now offers up enough resistance to slow the firing pin travel and cause the misfire, where the same would not happen if the hammer spring was still up to the task.

Wolff carries the spring, their website indicates that same spring was used in all generations (#27520 20# spring):

GROUP A Pistols - Long
For Use in:
39*, 439, 539, 639, 3904, 3906, 3944, 3946, 9mm
59*, 459, 559, 659, 5903, 5904 and 5906, 9mm
5923, 5924, 5926, 5943, 5944, 5946, 5967, 9mm
909, 910, 915, 9mm
645, 745, 4506, 4526, 4536**, 4546, .45 ACP
4566, 4567, 4576, 4586, 4596, .45 ACP
1006, 1026, 1066**, 1076, 1086, 10mm
410, 412, .40 S&W
4003,4004, 4006,4026,4043,4044,4046***, .40 S&W

*Early 39/ 59 pistols had a 22 Lb. factory spring.
** Some pistols may have short hammer springs
***Some 4046's have a 16 Lb. factory hammer spring.
•Reduced Power...: 16, 17 & 18 Lb.
•Factory Standard.: 20 Lb.
•Extra Power........: 22 & 23 Lb.

__________________
Conrad
SWCA #1830 SWHF #222

Inspect:
firing pin nose for damage, wear, rounding
firing pin channel for accumulation of gunk
firing pin head for damage, wear, rounding, "mushrooming"
Hammer spring for fatigue

Replace and clean said parts as needed.

As mentioned a change of grips makes no difference.

Sorry if it is obious (but I'm European) what is Hoppes #9?

A few years ago , I picked up a model 39 and was having problems with it sometimes not firing.. It was catching on the half cock notch.
I took it apart and gave it a good cleaning , always a good idea. It didn't solve the problem.
I asked the question on this forum and someone , ( sorry don't remember the name) suggested replacing the main spring (hammer spring) .. I figured for a few bucks why not ...

It has been working ever since.. hope this might help..

http://www.gunsprings.com/Semi-Auto%...1/mID58/dID261

high odor gun solvent made in Kansas, USA

I actually prefer the expensive spearmint smelling frog lube.

Thanks all! Cleaning worked, but I ordered the spring anyway as there was not much to clean. Anyway fired 2 full mags with no issue today.

Keep the slide rails well lubed, the 39-2 I had required it..