Hey guys, been hanging around this forum for a while but haven't posted at all.
Anyways, I have a S&W 686-6 "Mountain Gun" . 357. I inherited it from my father a year or so ago and it's been a great gun. Put probably 6-800 rounds through and it's a blast to shoot. It's just like any other 686 so far as I can tell only has a shorter lug under the barrel and was 1 of 250 released for a Lipseys promotion.
Anyways, it's developed a problem lately.
It seems like about one in every 15-20 shots or so misfires. When I inspect the primers it seems the firing pin is hitting just a little to the side towards the edge of the primer. If I fire the shell again though it will go every time. The firing pin seems to just not hit straight sometimes.
Anyone know what can cause this? I live in a remote area and gunsmiths are hard to find and I would prefer not to send it anywhere. I am very much a DIY type person so if someone could suggest a place to start I'd really appreciate it.
Timing and everything seems to be spot on. I just have no clue ain't this one.
Thanks in advance.

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Make sure the strain screw is fully cranked down.

Clean the gun if needed.

Does it have a reduced power mainspring?

As for:

"When I inspect the primers it seems the firing pin is hitting just a little to the side towards the edge of the primer."

A little off center is usually no problem, but I would definitely check the gun for carry up.

Does this happen in double action only or does it happen in both single action and double action? And does the cylinder have some resistance to turning? If the cylinder is getting harder to turn, you need to remove the yoke and cylinder and clean the powder fouling out. If you don't know how to remove the yoke and cylinder, it's easy to do and you can probably find bunches of YouTube videos on how to do so.

BTW, that is a really cool looking L frame with a half lug barrel. I wouldn't mind owning an L frame like that myself, even though I am partial to N frame pistols.

99.9% of the time a problem like this is due to a strain screw that has worked loose. This is especially a problem with Performance Center models which are shipped with the strain screw intentionally left loose in order to lighten the DA trigger pull but it can happen with any S&W that uses a leaf type mainspring.

The solution is to remove the grip and tighten the strain screw located on the bottom of the front strap of the grip frame as tight as is possible. Now, I will tell you that when you do this you will find that the DA trigger pull will get heavier. If you have a newer Firing pin in frame 686 you can expect a DA trigger pull in the 12 to 12 1/2 lbs. range if your revolver has the original factory mainspring. Some good news is that you can file fit the tip of your strain screw to lighten the DA trigger pull but this is a procedure that should only be done with the assistance of an accurate trigger pull gage and with a couple of spare strain screws on hand. Because odds are pretty good that in experimenting with this you will go a bit too far and that is when having a spare is really handy. Note, I tune my revolvers to have a 9 lbs. DA trigger pull to insure they will function reliably with even the hardest primers that can be found and I use an extended travel firing pin from Cylinder & Slide in my pin in frame S&W revolvers.

A loose strain screw is not going to cause an off-center FP hit that results in a FTF. Bountyhunter has the correct diagnosis in a carry-up problem. Check the cylinder stop notches to see if any are "peened" - this can result in the cylinder stop not engaging the notch and the cylinder may over-rotate, resulting in the off-center FP strike. If none appear to be peened, consider installing a new/stronger cylinder stop spring.

Adios,

Pizza Bob

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NRA Benefactor Member

Are you serious? Are they really shipping guns with loose strain screws as opposed to trimming and torquing them down, or bending the main spring?

I dont know when that MAY have been true, but ive shot thousands of rounds through 2 performance center guns and have yet to even check the strain screw for it backing out. On one, i haven't had the "need" to take off the sideplate. Both new "lock" performance center guns. Both incredibly reliable .

I haven't discounted scooters past experiences, i can only speak about mine. Its something ive heard before tho, hard to not dismiss this as internet myth.

But i dont think you'll find a "loose screw" in any new revolver today.

Thank you. That makes perfect sense. If the cylinder is over rotating it stands to reason that the firing would hit off center. I'll check that.
Also if that were the case (the cylinder over rotating) the pin would hit to the RIGHT of the primer correct?
The FTF cartridges always have the firing pin mark far over almost where the primer touches the edge of the pocket. Though I don't remember which side.

Hmm that's a hard question to answer. I typically do most of my firing in single action, though I did I do quite a bit of DA shooting this last range session and i'm 99% sure it happened in DA as well.
It definetely is not the result of powder fouling as I clean this revolver after every session even if I only fired 20 rounds. And yes my cleaning does include removing the cylinder and yoke every time.
I take exceptional care of this gun as it is a valuable heirloom and I enjoy it immensely. It is also my home defense weapon (along with my Mossberg 500 full of #4) so I keep it in tip top shape.
Though I am very familiar with the inner workings of numerous automatic pistols this is my first revolver and I haven't disassembled any further than the cylinder and yoke because it hasn't been necessary until now.

Carry up failures don't always over rotate, some carry up short. Unload the gun and slowly cock the gun at each cylinder position and watch and see if the stop (directly below the cyl) is locking into the notch every time. If not, you can twist the cylinder because it isn't locked.

Like I said, a shade off center is no big deal (the forcing cone handles it) but I don't like shooting guns with bad carry up just because.

There was a span of a 2 to 3 year period starting back around 2010 when nearly every week there was at least one post about misfiring Performance Center models. I also purchased a 625 JM in 2009 and while that was a PRo model instead of a true Performance Center model when I received my brand spanking new 625 the strain screw was 1/2 turn from being fully tightened. I think you can now understand my conclusion that at that time the Performance Center was shipping revolvers with loose strain screws.

Today folks are reporting that the Performance Center is using a mainspring that appears identical to the Wolff mainspring so that statement about guns shipping with loose strain screws may no longer be true.

Concerning off center hits, I have semi autos that don't hit perfectly on center and none of them misfire. I am also a reloader and VERY familiar with the shape of the anvil used in modern primers and am certain that a firing pin strike as far as 1/16 inch off center would still ignite a primer. I don't think this is a problem with carry up because any cylinder this far out of position would be shaving lead at the forcing cone. This is a problem with the primer not being hit with enough energy.

One thing that I didn't mention earlier is the potential of a worn strain screw or one modified by a previous owner of this particular revolver. My assumption was this was a brand new revolver. If it's one of S&W's stainless models then this problem could be quite possibly the result of a worn strain screw. It's been my experience that the stainless steel strain screws will have the tip "peen" to a shorter effective length after about 1500 rounds fired. Enough so that the burr formed in this process should be removed using a needle file while still in the frame to protect the threads of the frame when it's removed. I have now replaced all of the stainless strain screws in my revolvers with the harder blued steel screws because of this issue.

Not a light strike problem. The OP stated that the FP strike is near the edge of the primer. Since there is no ignition, there is no lead to shave - the projectile never leaves the case.

I had the same problem with a 625PC, which in some instances showed no primer mark whatsoever. It is more likely to happen shooting D/A, but can occur in S/A mode also. Being that it is more likely to occur in D/A, it may pass the test you recommend in S/A mode. Cylinder rotation momentum may cause it to over-rotate when shooting D/A, and you have compromised cylinder stop notches, stop or weak spring.

Mine was corrected by cleaning up the cylinder stop notches. After appx 4K rounds it started again. This time a cylinder stop and spring were installed. We're about a thousand rounds in since then and no problem.

Adios,

Pizza Bob

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NRA Benefactor Member

The OP described:

"When I inspect the primers it seems the firing pin is hitting just a little to the side towards the edge of the primer."

Which is a slightly off center hit, not near the primer edge. At least that's what it sounds like.

If the stop is so flaky that it is missing the notch, he should be able to load the cylinder with fired brass and snap off some DA pulls and get the cylinder to spin past which would be easy to see.

You are right!

The PC models use a similar spring to that of a wilson combat spring ( with a rib going all the way down)
Regular model use flat springs.
Those "ribbed" springs give great DA pulls depending on what trigger spring you use. I usually stick with a 14#r. And all models being equally internally will have different trigger pulls. Usually by .5-1.5#s

That's a good idea and I'll certainly try it when I get home from vacation. Didn't think of that.

Okay, reviving this thread.
Finally got a chance to shoot the Smith again.
It seems like it is only misfiring when shooting DA. Almost every time I shoot DA I'll get a misfire, when I look at the primer it will be hit right on the edge or between the primer and pocket edge.
Would this be a cylinder stop spring issue? It's not grabbing the notches on the cylinder hard or quick enough?
I also noticed the edges of the cylinder notches are kind of dented (for lack of better descriptive term). See pictures below.
What do you guys think? New cylinder stop and spring?
Also, I've noticed I'm getting some powder back spray when I fire, a minimal amount but still some. What would cause that?

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Strain screws are often a problem and people monkey with them to get light trigger pulls. But that ain't no strain screw problem.

It seems that the timing is bad and allowing the cylinder to rotate a little short or beyond the proper lock up causing way off center strikes and the shaving and powder blow back. So even the shots that are firing aren't firing right. Since S&Ws rotate to the left, I'd say you are getting a little over travel if the pictured brass haven't been moved.

It's funny, I just inherited a Colt Police Positive that doesn't quite make it to lock up, but if you push the cylinder, it snaps right into place. Gunsmith here I come for that one.

If you can't figure it out with the excellent advice given here, I wouldn't hesitate to send it to the factory. Call them and they'll send you a label to ship it to them.

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"He was kinda funny lookin'"

Okay, so the combination of those two things makes you think timing? I actually have a pdf file saved that has the whole procedure for checking the the timing. I remember going through it quite a while back and everything seemed within the specifications. I don't much care for the idea of sending it to s&w. In my experiences those types of deals take months not weeks.
I'm a pretty dedicated do it yourselfer and can figure most things out. Is adjusting the timing something a normal, reasonably intelligent person can accomplish or is it a gun Smith only type job?
As I stated before, this revolver was an heirloom from my deceased father and I'd very much like to keep it in tip top shape.
Thanks.

If you can carefully stone the flared up edges flat, on the cylinder stop notches, that may take care of the problem.

.

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Waiting for the break of day

Your picture tells the story, you have a failure to carry up or an issue with the cylinder not locking. My hunch is that it's a failure of the cylinder to lock up properly, most likely due to a slightly sticky cylinder stop. This is something that can be fixed with a good cleaning. However this is a rather "fussy" area of a S&W revolver to assemble and I don't recommend someone new to these revolvers fool around in this area.

Good news is that S&W has a LIFETIME warranty on these post 1989 revolvers and they pay for shipping both ways, so any warranty repair is at no cost to the owner. I would suggest calling S&W and arraigning a warranty repair. I'll also tell you to NOT waste your time emailing S%W because they don't have a good reputation in regards to email communications, they respond best and fastest to an old fashioned telephone call.

Further things to take note of. First, S&W shuts down completely in August and right now you are just in front of that shut down. So act quickly, as in today, and you'll have your revolver back before the shutdown. Second, make no mention of the fact you inherited this revolver. Technically that lifetime warranty only applies to the original owner but they almost never ask and I would regard your chain of possession as being of First Owner status.

Thank you for your advice. It could very well be a cylinder stop issue. I have never broke down the revolver enough to clean inside there. The most I have is removing the cylinder and yoke which I do every time I clean it. Should I just order a new cylinder stop and spring? Or is there any way to tell if it's sticky or just needs replacing?

Per previous advice I would send it in to S&W tomorrow. Here's why: 1. Any problems you are having will be solved and then some. 2. By doing your own gunsmithing you may void the warranty. 3. You have a beautiful gun, if it were mine I would not try to solve this problem myself. I have done quite a bit of gunsmithing myself and I've screwed some s$&@ up too. Most of the time it turns out fine but given what you've described I would send it to S&W for timing issues, it may be as simple as a new cylinder stop it may be the crane or the cylinder itself. Send it in, yes you'll have to pay for shipping and yes you'll have to wait but when you get it back it will be 100%. Just my 2 pennies.

Thank you. Very prudent and sensible advice. I will definetely take what you said into consideration.
I'm just very very hesitant to pack this gun into a box and ship it anywhere. It's very important to me AND I've been burned sending guns in to have warranty work done before.
I think i may try and find a smith specialist locally, falling that I'll call s&w.
Thanks for all your help.

Never do that "DIY" gunsmithing. That's like preforming surgery on your cat at home.

If I could only figure out where my cat's side plate screws are... I'm sure I could fix his hair-ball problem.

.

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Waiting for the break of day

Hey guys, so I finally got around to checking the strain screw. I was able to turn it about maybe an eighth turn or so. Is that enough to cause the DA misfiring?

I don't have snap caps so I put some already fired casings in there and did a series of DA pulls. I don't seem to be getting the off center primer hit anymore.. Could it really be that simple?

I was just looking at the pics Nicholi posted. That revolver is carrying past the cylinder notch. The cylinder rotates counter-clockwise. The off center strike is off to the right. A failure to carry up would give you an off center strike to the left. I would mark that chamber with a sharpie and try shooting again to see if the off center strikes are happening on random chambers or repeatedly on the same one. Off center strikes in random chambers would point to a cylinder stop problem. Off center strikes happening at one particular chamber could be several things, such as a damaged or mis-cut cylinder notch or extractor star gear.

If you look carefully at the cylinder stop slots in the photograph you'll see some damage. Peening on the stop slots is fairly common, and is more prevalent in revolvers with large, "heavy" cylinders, like the L frame and the model 27, and 28 N frame models. The extra weight of the cylinders in these models can play hovoc with the cylinder stop, stop slots and the stop window in the frame....not only during firing, but during opening and closing of the cylinder assembly. This is the "achilles heel" of the L frame, I believe.

Due to this damage, the stop may not be holding in one or more of the slots in the cylinder. Another possibility is the stop is not coming up far enough to fully enter the slot itself and "hold" after entry. (the stop can be "let out" to help it rise higher above the frame, and deeper into the slot) Could also be an issue with the cylinder stop spring.

In this case, I would agree with the previous members who suggest sending the gun to the factory for evaluation and repair.

My guess is, there are multiple issues here, along with the battering/peening visible in the cylinder stop slots.

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Ret. LE, FA Instr, S&W Armorer

Well it seems the strain screw didn't fix the issue and you guys were obviously right. I have a timing issue as well. If I pull the hammer back slowly the cylinder will lock BEFORE the hammer is fully cocked. But if I put slight resistance on it and do the same thing the cylinder will not lock up before the hammer is back. It's probably a millimeter or less of movement before it locks but it's there.
I called Smith and Wesson and they emailed me an overnight shipping label. He said the factory shutdown is until August 5th. So i will mail it on the 4th.
Im bummed that I have to mail it in but it will be factory fresh again so that's a bright side.
They said since it was an inherited piece from my father who bought it new they will honor the warranty.
Thanks for all your help guys. Much appreciated.

Glad to hear you are letting the mothership take a look at it. They will fix it right for you. I sent my old 27-2 back to them a year ago after having it for 40+ years and many rounds through it and they did a stellar job freshening it up and made it feel new again. And although it cost me, it was still very reasonable on cost and I'm fully satisfied with the work they did on my treasured old 27-2.

I lived in New Zealand's South Island for a year. Lived with a Māori family on their sheep ranch, I worked as their shepherd and did other jobs.

Anyway the old man told me to get only one 'gumboot', (rubber boot), he was holding one of the farms cats. He said "hold the boot still" and he dumped the cat in head first. What the...?

Next he got out his pocket knife and slit the cats nut sack open, grabbed the two nuts and pull them clean off, like starting a lawn mower.

He said dump the cats out and get me the other one. We never saw the other cat again. The cat lived and did ... well he lived.

True story.