So your decock doesn't work anymore...Now what?

[BMCM]

Well, I'll tell ya whut

Hiya Gents,

So I have a member's CS9 here on the bench for some fixin' up and a new set of sights. I got everything done and was going about the op check and lo and behold the decocker is out of time...as in no worky Well that's no good at all so here's what we do to fix that. Kinda convenient that I have this going on in light of Oscar Zulu just posting about the same problem.

Anyone guess what's wrong with this picture?

Yeah, that hammer should not be cocked. So, if I grab it like so...

And give it a little pinch there, the hammer decocks.

Sure we have a little vertical slop between the slide & frame here and that's quite normal. But more importantly this tells me the sear release lever is too short. Could be from normal wear or improper fitment or a combination of both. I'll not bother gauging timing at this point... just going to proceed with fitting a new lever.

Sear release lever... part number 104030000 it's this little doodad here.

Now to take it apart to get the bad lever out of there. Sideplate needs to come off but I want the sear & sear pin to stay put, so a light smack with my squishy hammer....

Takes care of that.

Set the lower in my vise and use an old 6906 sideplate for a slave pin to shove the CS9 plate out while keeping everything in alignment.

Now walk the slave pin out to the right removing the ejector then the hammer assembly. Now I can pick the bad lever out with some forceps.

Here's the old lever stacked on top of the new replacement on a hammer pin. You can see the new lever has a good deal more meat and more significantly the angle is different. That difference in the angles tell me the old lever was not fitted properly. it's very important to NOT change that angle when fitting a new lever.

First order of business, just stick the new lever in there to see where we're at.

Put everything back together and break out the pin gauges to check timing.

Going right to the 0.078" gauge to check for early decock. With the hammer cocked, stick the gauge pin in the recess right below the decock lever and attempt the decock the hammer.

As I expected... Early decock. Decocking early is bad because the hammer is falling at a point where the firing pin is not captured by the decocker body and shielded from hammer strikes. In order to correct that, out comes the lever for some adjusting. I set the lever in a machinists clamp and with a 3cut swiss pillar file take a few strokes. Have to take great care to keep the file level and not roll the edges of the lever. And NOT change the angle at all. I case you're not sure... were filing on the little flat surface sticking up between the jaws there.

This is a trial and error process. You only remove a minuscule amount of material at a time. Adjust the lever, assemble, gauge it, rinse & repeat until the timing is in spec. After filing I still had early decock on the 0.078" pin so pulled the lever and hit it with a extra fine india stone. Reassembled the second time and gauged with the 0.078" pin... No decock, good so far. Now gauge with the 0.045" pin... Normal decock function. There's no need to check it with the 0.025" pin.

And... We're done, well still awaiting delivery of the new front sight, so mostly done

Just to more clearly illustrate what's going on in there...

When you cycle the decock lever it in turn presses down on the sear release lever which acts against the top of the sear shoving it forward out of engagement with the hammer's full cock notch.
Simple huh

Patience is the key here... It's very easy the remove too much when filing the lever and ruin the lever. In which case you've got no choice but to bin it and start over with another new lever. Fortunately they're cheap

Cheers
Bill

 

[Jeppo]

I'm learning so much from your posts! I have an old Gen3 I'm working on and finding numerous parts that need replacing. When I yanked the sear lever, I found one edge completely burred. Not sure whether that's from wear or extremely sloppy fitting. Anyway, I ordered some levers last night.

I do have one question about the last photo though...

Mounting the sear lever as shown, how can I get the slide to cycle?

 

[18DAI]

Gun fails to decock? I Email BMCM - IMMEDIATLY!!

Another excellent tutorial! Thank you sir! Regards 18DAI

 

[Sevens]

This guy is amazing... and uses his photo and posting skills to share his REAL skills in tutorials that other folks would package up and market for sale.

These pistols need a BMCM logo (an anchor!) before getting shipped back.

 

[BMCM]

Ok ok... Well I did have a little stamp made up...

It about fills a 3/16" square. Will this do?

Cheers
Bill

 

[Sevens]

Haha my gut reaction is "hell yeah" but I think just about anyone/everyone wants to see what such a stamp leaves behind when used!

 

[BMCM]

On steel....

Cheers
Bill

 

[Sevens]

Well, I'd choose something a little more pronounced, but to be honest, I'm glad the idea has gotten this far. Carry on! :thumbs up:

 

[GaryS]

Another great post, thanks.

A sort of question. Since I don't have a set of pin gauges and don't have enough need to justify buying a set, I did some (always dangerous ) Internet research.

From what I can tell, a 5/64 drill bit is very, very, very close to a 0.078 gauge. A #56 drill bit is very, very, very close to a 0.045 gauge. If there is someone who has both pin gauges and drill bits who can double or even triple check me, I'd appreciate it.

BMCM, you make this stuff look too easy.

 

[Sevens]

BMCM, you make this stuff look too easy.

I'd just like this part to be seen again.

 

[Rule3]

Excellent post,

but could post some better pictures? LOL

 

[BMCM]

You can get those three gauge pins in class Z from McMaster-Carr for about $13.

I prefer to stay spot on the factory dimensions here. Your dealing with tiny increments and even a minuscule bit of error or deviation can leave you outside the safe timing range. I don't think "close enough" is acceptable here.

Class Z plug go gauges:
pn: 23055A001 inch size 0.025" $4.35
pn: 23055A001 inch size 0.045" $4.35
pn: 23055A002 inch size 0.078" $3.89

Cheers
Bill

 

[Fastbolt]

BMCM's post is similar (but better illustrated) to what was taught in the armorer manual toward the end of the 3rd gen production. Nice.

(Note the easy way to lightly whack, snap the headed end of the sear pin out from between the legs of the sideplate, too. I use a hard yellow plastic mallet, myself.)

Armorers could order a set of regular numbered metal drill bits to use as the gauges, meaning using the non-cutting ends. The bits needed were .025", .045" & .078", and they could be used as Go/No-Go gauges to check decocking timing, and when fitting/filing a new lever.

If the hammer didn't decock using the .025 bit (non-cutting pin end as the "gauge"), a new lever was needed.

The hammer should drop when the .045 pin was used, but not when the .078 pin was used.

In the days before S&W came up with the idea of using the numbered metal drill bits as gauges, armorers were taught to gauge the timing by eye ball. Applying steady pressure against both sides of the left safety lever, the lever was very, very slowly lowered (against resistance of the opposing thumb) until the hammer dropped, at which point the lever was instantly released. (It typically wouldn't be all the way down.)

If it was a spurred hammer, the armorer than used the spur to pull back and release the hammer (to snap forward) a couple of times. The force of the hammer snapping forward (against the rear of the manual safety body, under the hammer face) ought to be enough to "finish" having the safety lever "drop" the rest of the way down. If not, another file stroke on the sear release lever's leg was needed.

For the early 3rd gen spurless hammers (which had serrations across the top), the armorer could use the edge of his armorer's wooden wedge to grasp the serrations to pull back the hammer and let it snap forward (usually once or twice would let the safety lever finish dropping down).

Another way suggested for the older spurless guns was to use the tips of the #2 & #4 cup-end pin punches provided in the S&W armorer kit as defacto Go/No-Go gauges, in the same manner as later used with the numbered drill bits. (The pins might vary in thickness from time to time, though, depending who made them.)

Often the lower (rear) edge of the manual safety/decock lever could be eyeballed to approach within a certain distance of the front of the red painted ball on the frame in order to reach the needed decock timing.

Eyeballing the lever, and trying to move it downward slowly enough to gauge when decocking timing had been reached wasn't as easy for some armorers as for others, and the eventual decision of the training academy (which runs the armorer training program) to use the numnbered bits/pins made it easier to learn to gauge the timing.

The laborious part of the process was the reassembly of the gun to check the timing, and then disassembly for an additional file stroke (or two, if the lever leg was on the long end of the tolerance range). Armorers were also told to insert and seat an EMPTY magazine in the gun before checking the decock timing each time, to check the timing in as close to actual conditions as possible. (Instead of repeatedly installing and removing the grip each time, I used an old trick of getting an older series backstrap to use to contain and seat the mainspring to check decock timing.)

It's really easy to make the "one-file-stroke-too-many" and ruin a lever, and then have to start over.

It was also helpful when S&W started making the new sear release levers to a tighter set of tolerances (as the 3rd gen tolerances improved), instead of older days when the early 3rd gen guns had looser tolerances, so the legs were made overlong and might require a lot of filing.

The trick still remained for the armorer to position the lever's leg facing upward, just above the vise jaws, oriented so the 1-way file strokes would be maintained at the original factory angle cut on the bottom of the leg. Changing the angle in any way could affect proper decocking and mess things up.

As armorers sometimes discovered in the older production 3rd gen's, if a lever was fitted on the short end of the normal range it might wear down and require replacing much sooner than if the lever had been fitted more on the longer end of the normal range. Kinda depended on how rushed the assembler fitting the sear release lever might've been when working on any particular gun.

 

[Jeppo]

You can get those three gauge pins in class Z from McMaster-Carr for about $13.

Thanks for that. I think I've ordered them (meaning their site isn't very sophisticated for e-commerce). Let's see what happens.

 

[GaryS]

Thank you. I am going to order them. My search-foo was weak because all I could find were complete sets.

For the price they cost, it makes no sense not to have them even if I don't plan to do anything approaching the type of work you do.

You can get those three gauge pins in class Z from McMaster-Carr for about $13.

I prefer to stay spot on the factory dimensions here. Your dealing with tiny increments and even a minuscule bit of error or deviation can leave you outside the safe timing range. I don't think "close enough" is acceptable here.

Class Z plug go gauges:
pn: 23055A001 inch size 0.025" $4.35
pn: 23055A001 inch size 0.045" $4.35
pn: 23055A002 inch size 0.078" $3.89

Cheers
Bill

 

[Jeppo]

Gary,

The one caveat is that there's no way to know how much they're going to charge for shipping. It isn't indicated on the site and even the confirmation email I received simply says "Applicable shipping will be added".

If you like, I'll come back here and post the total damage once I know.

 

[GaryS]

I saw that when I placed the order. Hopefully it won't hurt too much!

Still worth having, though.

Thanks.

Gary,

The one caveat is that there's no way to know how much they're going to charge for shipping. It isn't indicated on the site and even the confirmation email I received simply says "Applicable shipping will be added".

If you like, I'll come back here and post the total damage once I know.

 

[GaryS]

Yes, it takes a bit of work to order from them. One part number for multiple sizes is a bit confusing. Oh well.

Thanks for that. I think I've ordered them (meaning their site isn't very sophisticated for e-commerce). Let's see what happens.

 

[oink]

A very nice lesson. Thank you.

Being the the bubba smith I am, I wonder if the lever could have been stretched enough to get it working or is the metal too hardened?

 

[BMCM]

A very nice lesson. Thank you.

Being the the bubba smith I am, I wonder if the lever could have been stretched enough to get it working or is the metal too hardened?

You're welcome.

As to your question, I imagine you could...you'd have to anneal it first then then re-harden after stretching. The if you're off the mark on the hardness level it'll either wear out quickly or saw a slot in the sear leg.

We're talking about dimensions of just a few thousandths so I'd say stretching is more trouble than it's worth for a three dollar part.

Cheers
Bill