686 Lock-up Issue

[Versalog]

My 686 (year of manufacture: 2010) locks up about every five or six shots. I have to manually rotate the cylinder about an eighth of a turn to re-set something and then it's fine for another five or six shots. I can dry fire it endlessly without this happening. Any thoughts on this? Could it somehow be related to the internal lock?

 

[Rpg]

I doubt the IL has anything to do with what's happening.

 

[hittman77]

Clean under the ejector star?

 

[MetalMan]

Perhaps a timing issue exacerbated by a fully loaded cylinder?

 

[steelslaver]

Just to get this right does the lockup occur when shooting double action and it won't complete the trigger pull?

Won't cock all the way in single action? These could be a occasional high primer or a slightly long ratchet tooth.

Just fired a round and it won't start to cock and turn to another chamber? Possible late locking bolt movement or sticky bolt. Burr by trigger return slide.

Have you tried to figure out if it one particular chamber?

Absolutely no tight spots dry firing?

Under ejector star really clean, face of cylinder clean? Debris pressing back on ratchet and cases making timing fast or case heads rub.

If you stick feeling gauges between rear of cylinder and recoil shield what is measurement? Tight headspace

No burr by firing pin bushing? Drags on case head.

Cylinder face rear of barrel dirty or dragging?

 

[UncleEd]

Answer all of Steelslaver's questions.

But first answer the one about being absolutely
sure the area under the ejector star is clean, clean,
clean and dry, dry, dry.

 

[haywood]

Make sure the action is clean. Flush it good with gun scrubber then lube. My standard answer. You probably did that .

 

[cmj8591]

Assuming hat the gun is clean, check the barrel/cylinder gap. If it is too tight, as the gun warms from shooting and everything starts to expand it will begin to bind. That explains why it dosn't lock up during dry fire.

 

[UncleEd]

I've seen far more revolvers fail than good quality semiautos. And when a revolver fails it usually means it's catastrophic, which means its user is outta the fight, which usually means it's gonna turn out bad for him.

SA1911, you need to be spanked for talking naughty
on Christmas Day.

 

[Versalog]

686 Lock-up Issue REPLY

All,

Thanks for the suggestions.

It locks up periodically when shooting double-action and when I try to cock the hammer in single-action. It doesn't discriminate.

Absolutely no tight spots when dry firing.

It's not one particular chamber.

Ejector star is nice and clean.

Both faces of the cylinder are shiny clean.

No burr by firing pin bushing.

I don't think it's an occasional high primer...it's too regular for that.

The timing issue exacerbated by a fully-loaded cylinder is interesting. What can I do about that?

Again, thanks for all the feedback.

 

[hittman77]

What can I do about that?

Call S&W for service.

 

[Protocall_Design]

That one is pretty hard to diagnose long distance. Where are you located? Maybe someone is near enough to help.

 

[cmj8591]

All,

Thanks for the suggestions.

It locks up periodically when shooting double-action and when I try to cock the hammer in single-action. It doesn't discriminate.

Absolutely no tight spots when dry firing.

It's not one particular chamber.

Ejector star is nice and clean.

Both faces of the cylinder are shiny clean.

No burr by firing pin bushing.

I don't think it's an occasional high primer...it's too regular for that.

The timing issue exacerbated by a fully-loaded cylinder is interesting. What can I do about that?

Again, thanks for all the feedback.

Get a feeler gauge and check the gap between the end of the barrel (forcing cone) and the face of the cylinder. It should be no less than .004 inches, and ideally, around .006" but never more than .010". Even if it gauges at .004 it may still not be enough if your cylinder is a little sloppy. I'm going to go out on a limb and bet you a nickle that is your problem. If it is, it's a quick fix involving a file and a steady hand.

 

[UncleEd]

CMJ has a good thought, check the spacing between the
forcing cone and front of the cylinder.

One suggestion for a quick review is make sure the
front of the cylinder is clean, shiny, and then blacken
it with a Sharpie pen.

Put in six empty casings and then start the rotation.
See if one chamber area is scraping the Sharpie
markings off.

I remember a Model 27 that had an uneven cylinder.
I filed the offending front chamber area just a bit and
fixed the dragging problem. Not saying this is the
problem but if it is, Smith & Wesson will fix it for you
right quick.

 

[overthehills]

Just a thought, when I have seen this happen, it has been caused by a fired case sticking both out too far & bound up in the charge hole making a snag against the recoil shield as the cylinder would rotate & try to guide a protruding spent case back in on rotation (usually a 357 case after several 38s had left a stubborn carbon ring in the charge hole.) Excess headspace (dread the thought) will cause this too. I gotta with steelslaver...dragging on the caseheads here somewhere Good Luck & keep us posted

 

[JDinAZ]

You may have a weak cylinder stop spring. Almost sounds like the ol 44 mag cylinder rollin backwards problem that they used to have before the performance package was done in around the -3 era.

 

[Versalog]

All,

Again, thanks for your input. My revolver has been to a gunsmith twice: once he removed the side plate and cleaned and removed the rust from whatever mechanism is beneath the side plate. The gun would still freeze. Next he put a shim of some kind near the trigger assembly. This, too, did nothing to help. I'm going to contact Smith & Wesson tomorrow and presumably send in the gun to let them try to fix it.

 

[4011]

Make sure the ejector rod is tight. Also see that the gun is cleaned.
Had my ejector rod backed off more than once. Range master pulled my from qualifying once cause I was slowing the auto shooters down.

 

[Versalog]

RESOLVED: 686 Lock-up Issue

All--thanks for all your input. It took four months but I finally got my revolver back from Smith & Wesson. The document I received said they had to "repair the cylinder endshake." I'm not sure what that means but my gun fires perfectly now.

 

[CelticSire]

Here's the best explanation of what endshake is and why it can cause the issue you experienced.

From Grant Cunningham:

The importance of endshake. - www.GrantCunningham.com www.GrantCunningham.com