Picked up a lightly-used Model 59 from Gunbroker.

First range trip.

Experienced three mis-fires over the course of two magazines.

Inspected pistol before range trip.
Generally clean as received from seller - possibly a little bit dry.
I wiped it down on many of the contact surfaces.
Applied a little Break Free to the rail-channels of the slide.
Applied a little white Tetra grease to the lug areas of the barrel and slide.
Applied a little Break Free to magazine disconnect lever and the second lever (forgive me I don't know the name - it will trip the hammer if I push it while the hammer is cocked).

Dry fire action appeared correct.

Here is one of the rounds that mis-fired, and a couple cases that did fire.

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By contrast, and lest somebody may suggest "hard Wolf primers" here are three fired cases of the same ammo fired in a Glock 17.


(EDITED TO ADD: The primer on the left looks like it came from a Glock. The other two, I believe were in fact fired in the Model 59, and are just showing that mysterious extra "tick mark" by the primer indentation, and that still showed up again after the new Wolff spring was installed.)

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Here are some more photos showing other related parts that may offer clues.

Mainspring


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Firing pin return spring
(and note that firing pin channel was void of debris)


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Firing pin is unremarkable - rolls true on flat surface - tip is undamaged




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Not seeing any issues with the selector.


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Firing pin channel
(slide is upside down for photo)


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Recoil spring and guide rod.

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Suggestions/info greatly appreciated!

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Allow me to add a couple things.

I did not observe any out-of-battery condition at the time of mis-fires -- but not that I was looking for such condition closely. I am aware that a slightly out-of-battery condition may cause light strikes.

I don't think I was limp-wristing the gun. I am aware that limp-wristing can contribute to out-of-battery incidents.

The gun is equipped with Pachmyr wrap-around grips -- which make the the grip as fat as a fence post unless you have gorilla hands. I am planning on replacing the Pach's.

I used two different Mec-Gar mags, and I experienced mis-fires with both mags.

If I can think of any other wild-card variables over the course of the evening, I will add them to this thread.

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I'd just get a new hammer spring and possibly a firing pin return spring that would be tuned with the new hammer spring....say from Wolff. I think your hammer spring is just a little weak is all. Any time this has happened with any of my guns, it's nearly always just a weak hammer spring.

My only suggestion is buy a spring kit from Wolff...about twenty bucks. Odds are the mainspring lost some oomph over the course of a few decades. Try some different ammo also. If the cases are a little short the headspacing will be off...allowing the case to sit deeper in the chamber. Have you tried the pencil trick? cock the unloaded gun, point to ceiling, drop pencil down barrel (eraser end first), squeeze trigger. Does pencil jump significantly?

Cappy

Oh lord.

The pencil trick.

Someday, I'll tell you the story about how I once during a trial launched a Bic "Stic" pen in such a manner that it landed as a "hole in one" in the globe of a courthouse chandelier.

I'll go put the 59 back together and try that - just not in the Courthouse this time.

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That image of the ammo you posted....are the primers seated a little deeper on the cartridges that didn't fire? It looks that way to me. Just another shot in the dark. I know how frustrating gun malfs can be and am trying to offer a little support....stick with it, you'll get 'er to run right. Model 59's are cool...I have two model 39's that fit me just right...my hands are on the small side.

No primer-depth issues that I can see.

Same dented-primer round as the previous pic appears here.

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I'd be surprised if its the ammo or the grips.

Although, I do already have a set of Uncle Mikes rubber grips on the way.

Should fit my hand better than those Pach's. Whose idea was it anyway to put a great big bulge for a thumbrest on BOTH SIDES of a grip for a pistol that is already fat as can be? This grip is so big, its like hugging a "big girl" already, and Pachmyr has to make her wear an inner tube to boot?

At least with different grips I should have a better hold on the gun, and less likely to limp-wrist. If I'm limp-wristing to cause some sort of partial-battery issues, it would be a first for me after never having experienced it with a dozen or so other double-stack guns. I have a 659 that wears the Uncle Mikes, and the feel is much better - although the 659 is having other types of issues I'll write about later this weekend.

I detail-cleaned the 59 after I shot the pics. Hard for me to believe it could be a dirty-gun issue, as there was very little fouling on the gun. Just a little of what looked like a waxy bullet-lube on some of the camming surfaces, a few spots on the rails, and around muzzle bushing.

The mainspring sure LOOKS good, but I think I'll go ahead and switch that to a Wolff spring before I go to the range again.

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W.E.G.,

Please be sure to let us know the result of your next outing after your hammer spring changeout. I'm very curious to know the outcome.

I certainly will do that.

I ordered the $13 set of hammer springs of various spring weight
at Springs for SMITH & WESSON NUMBERED SERIES Semi-Auto Pistols

Reduced & Extra Power (Stock No. 11412)
This pak contains 1 each of 16, 17, 18, 20, 22 and 23 pound hammer springs listed above for Group A model pistols, allowing complete adjustment of the firearm to individual requirements.

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.

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Springs came today.

Might range-test tomorrow.

Installed the 20# spring that is listed as the "Factory Standard."
new spring in foreground

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Uncle Mikes grips came too

Gun is still a bit corupulent, but not nearly as annoying as the Pachmyr grips with the thumb shelf on BOTH SIDES of the grip.

Looks "all busisness."

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WEG, the gun looks good to me. Let us know how that new hammer spring works out.

Some thoughts ...

In your images posted the hammer spring looked factory but the firing pin spring did not (no flattened, "closed" coils visible on the ends of the spring). Might be related to your problem ... might not. Replacing it with a stock firing pin spring might have demonstrated something, though. Never know.

If it were me, I'd have used a different brand of ammunition to function test the gun before starting to think it might be a gun problem ... one of the major American made ammunition lines ... but that's just me. Might as well try to eliminate as much of the potential for an ammunition-related issue as possible before starting to replace things on the gun.

BTW, how did the sear spring appear when you had the grips off? Not curled at the top or split, right? (Not implying it could be related to your condition, but just thought I'd ask, considering the vintage of the gun and the importance of the sear spring.)

Don't mistake the different length of the Wolff mainspring (hammer spring) compared to the original spring to necessarily indicate the old spring had gone "bad". The different gauge and windings can result in longer springs without necessarily being any stronger in actual force. A gentleman at Wolff reminded me of that in years past when we were discussing some differences in length of new factory spring versus their company's springs made to produce the same tension.

I couldn't see the rear end of the firing pin. Not peened or mushroomed, is it?

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Good suggestions.

I'll give all those a good inspection after the range trip.

The firing pin shows no mushrooming or other damage.

Honestly, I don't plan on using ANY "major American lines" ammo for casual range trips unless I absolutely have to. I shoot 9mm pistols at big targets that don't shoot back, and at close range. I just need it to go bang, and cycle for the least amount of $$$, and without having to spend time at the reloading press.

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New spring is hitting those Wolf primers like a champ now!

Ran several mags trough the Model 59 today, with 100% go-bang.

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Last week I noticed that the Model 59 was leaving an "extra" mark on the primers.

Still doing it with the new spring.

Wonder if the primer is hitting the corner of the extractor or some such on the way out?

Note mark on primer at around one o'clock relative to the firing pin indentation.

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W.E.G. I don't know if you installed that new firing pin spring or not when you replaced the hammer spring.

But I do understand that sometimes when a mark is left on the primer like that, it means that the f.p. spring is too weak to return the f.p. back to it's place before ejection can happen and so the f.p. leaves a mark when the mty case is on it's way away from the breach face.

You might try that new spring and see if it helps; however, the dimple does not hurt anything. Sounds like you've got the main problem solved.

The only spring I changed was the hammer spring.

The firing pin spring used so far is whatever spring was already in the gun when I received it a few weeks ago.

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