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

__________________
Because they don't make a .46

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?

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

Another excellent tutorial! Thank you sir! Regards 18DAI

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7 +1 Rounds of hope & change

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.

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



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

Cheers
Bill

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Because they don't make a .46

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!

On steel....



Cheers
Bill

__________________
Because they don't make a .46

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:

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.

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Can open, worms everywhere.

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

Excellent post,

but could post some better pictures? LOL

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Still Running Against the Wind

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

__________________
Because they don't make a .46

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.

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Ret LE Firearms inst & armorer

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

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.

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Can open, worms everywhere.

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.

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

Still worth having, though.

Thanks.

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Can open, worms everywhere.

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

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Can open, worms everywhere.

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

__________________
Because they don't make a .46

A random thought after reading both Fastbolt and BMCM's posts. If one had a mainspring cup from a set of Hogue grips, could that be used instead of putting the entire grip assembly back on every time?

Then, once the timing is confirmed, remove that and put the Delrin grips back on.

As I said, a random thought.

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Can open, worms everywhere.

Never tried it that way, but as long as the factory mainspring cup (plunger) plunger is still inside the Hogue base and the base pinned in place, I don't see why not. Careful not to pinch your skin when cocking the hammer with the exposed mainspring.

The Hogue base is just the support for the factory mainspring cup (plunger). A common couple of mistakes that sometimes happens is that someone forgets to use the factory mainspring cup (which is really called a "plunger", BTW, if you haven't already noticed it mentioned. ), and/or they forget to still use the factory grip pin when they install the Hogue grips.

The mainspring plunger sits against (on top) of the detent ring of the grip pin, which supports and gives full tension to the spring under the cocked hammer.

While some guys used to cut up an old "pre-dimple" factory grip, cutting the sides off to make an armorer's backstrap (to check the decocking timing), I used a 469 backstrap we had left laying around. It's short, sure, but it was just needed to support the mainspring plunger, mainspring and hammer/stirrup while checking decocking timing. This way the sideplate wasn't subjected to having the top of the left side of the grip rub up against it, and risk snagging under the front of the sideplate. That's what usually tweaked and bent or broke off the rear leg of the sideplate's legs, caused by inattention when installing the 3rd gen factory grip.

They used to stress that getting the right timing was important enough, that they even told us to insert & seat an empty magazine in the reassembled gun when checking the decocking timing.

Better safe than sorry when you're working on guns.

__________________
Ret LE Firearms inst & armorer

Brings another question to mind. I have a very early 669 that has seen a lot of use. Care to suggest a parts kit worth buying while they're still available?

Yup, that's what I do. Got a couple spare cups from Karl Nill too, they're nicer

Cheers
Bill

__________________
Because they don't make a .46

You're always helping us to find new ways to spend money!

Off to search Karl Nill.

And now, to drag this out further...

I did some testing this morning using the drill bit gauge. I tested my 3914NL and the pre rail 3913TSW.

The TSW has had the ambi safety swapped out for a left side only safety. Thus my interest in making sure everything is within spec.

The 3914NL easily passed the "no go" test, but the TSW did not. That did pass the "pencil" test and seems fine using the "red dot" test.

I then did an eyeball comparison of the two safety levers. The TSW safety is a bit "thinner" on the side of the body than the NL.

Then is struck me. I sent the safety to BMCM for a bit of a shave and dehorning. Which came out beautifully, BTW.

Noticing that the very tight tolerance and the need to be very, very, very, careful with the filing of the sear release lever, I have to wonder if the little bit of shaving done in the dehorning process accounts for this?

Note that I am not even in the least questioning the work BMCM did for me. It's excellent. I just wonder if that little bit of shaving of the safety body is what is account for the difference.

What do you think BMCM?

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Can open, worms everywhere.

Your "no go" test....describe how you went about that?

Here's the gauge checks and results

gauge on 0.025" pin - weapon decocks - ok but near lower limit

__________________
Because they don't make a .46

For both firearms, I used a 5/64 drill (pending arrival of the guages) placed as shown in this picture.



Note that I used the forceps to improve the picture clarity. When I do the test I hold the bit in my fingers.

Here are the 3914NL and 3913TSW decockers side by side. It's a big picture because the difference is very small. I just wonder if the tiny difference accounts for the "no go" fail?



I'll redo the measurements when I get the guages.

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Can open, worms everywhere.

Sounds like you know what you're doing. I understood the "no worky" part, but everything after that was "rocket science" to me.

Your "no go" test....describe how you went about that please?

Here's brief rundown on the gauge checks and appropriate action...

gauge on 0.025" pin - decocks - in spec but may be in need of
new lever soon, verify with 0.045 pin
gauge on 0.025" pin - fails to decock - fit new lever
gauge on 0.045" pin - decocks - in spec
gauge on 0.078" pin - decocks - too early, file lever
gauge on 0.078" pin - fails to decock - good, in spec so far,
verify with 0.045" pin

The portion of the safety decocker bodies external to the slide has no bearing on the mechanics of the decock function. Thus Any shaving of the external levers has no effect on the function.

Take a look at this lever assembly...

Note the slot on the right hand side I'm pointing to with the punch. That slot provides clearance for the sear release & firing pin safety levers as the slide cycles during firing. In decocking, the forward edge of that slot (note the shiny spot right on the leading edge) bears downward on the sear release lever as you rotate the decocker body. Even if there is wear evident here, the corrective action is still fitting a new sear release lever to the gun.

Cheers
Bill

__________________
Because they don't make a .46

I did the test exactly as shown in your first post.

Now I see where I went wrong, in my question. The lever thickness is not related to the decocking function, it's just a convenient was to measure what's going on inside the gun.

Got it. I think.

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Can open, worms everywhere.

Well, that's weird...
Seems the system posted up #26 while I was just starting to type it up... #29 is the end product I was shootin' for

Gary... I see where there might be some confusion here... I don't view these checks necessarily as 'go' / 'no-go' I was a little confused on exactly what you had done and did not know what you meant by pass/fail... It's not a pass/fail test it's a gauge check that yields a result which tells you what action to take next.

So if you were checking those guns with a 5/64" bitt, know that 5/64" is a tenth larger then 0.078" so there's that.

Now if one gun decocked on the 5/64" pin I'd suspect early decocking in which case that gun might need some adjusting on the sear release lever. However, I'd want to check it with a proper 0.078" gauge pin before modding anything. That 0.0001" might be the difference.

Same if the other gun the did not decock on the 5/64" bitt. OOK so is ok but I'd still want to make sure it will not decock on 0.078" gauge pin.

I note you had changed the decocker body on the TSW gun. When you say that gun failed the "no-go" test does that mean it
decocked or not?

Basically you want NO Decock on the big pin, YES decock on medium pin, and the small pin is the check to make sure a well worn gun will still decock. If you have NO decock on the small pin...time for a new lever. Does this help?

Cheers
Bill

__________________
Because they don't make a .46

I think I'm confusing you with my imprecise terminology.

I am going to wait for the gauges to arrive before I make any determination on what, if anything, needs to be done. I got the receipt today, so the package should be on its way.

(For Jeppo, shipping and tax was not bad at all.)

The gun that did not decock (3914NL) has been unmolested by me, so I expect it's within the timing parameters you've laid out. The TSW is not within parameters (with the Micky Mouse gauge ). I'll recheck both, as well my other 3rd Gens, with the proper equipment.

In the mean time, I can carry my 3914NL, which I should do more anyway.

I have a couple of sear release levers on the way from Numrich, but again, I'll do nothing until the gauges arrive.

Sorry for confusing you, and as always a big thank you for sharing your knowledge.

I don't know if you did any formal instruction when you were in the CG, but you are a detailed (and patient) teacher. I know I appreciate it that, and I'm sure that others do as well.

I'll report back when I have the gauges and have re measured.

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Can open, worms everywhere.

To my joy and surprise, the package from McMaster-Carr came this afternoon via UPS. Fast service.

Anyway, using the proper gauge and holding it in the right position, the TSW decocker is within spec. If have to make sure it doesn't "skid" out of position, but it appears fine.

A couple of valuable lessons learned the painless way!

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Can open, worms everywhere.

They used FedEx in my case. $7 shipping for that level of service seems more than reasonable to me. Looking forward to expanding my education over the weekend.

Got my 908 back together tonight, including a new plastic disconnector and the previously replaced sear spring and pin. Ran it thru the decock tests with my fancy new pin gages and, "Houston, we have liftoff".

Thanks everybody!!!

If one is like me, and should not be allowed to do stuff like this to anything more sensitive than an anvil, the smart answer is to ship the item to Bill with a check for his estimate and call it a good decision. Done it once already, and when my recovered stolen comes back in a few weeks, I'm going to send it to him for a good once over. No telling what 7 years in the "care" of others did. Worth the money and time in peace of mind.

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NHI, 10-8.

Is that one edge of the sear the only part that needs fitting? I got my replacement part 104030000 and when I tried to put it into my 915 to see how it worked, I could not get the slide back on. It hangs up at the hump part of the top of the sear release lever. I was pushing it down fairly hard with a punch to no avail.

Attached Images

IMG_20181205_080603.jpg (49.5 KB, 43 views)

Yes, only the "foot" of the sear release lever is filed or stoned to effect proper decock timing.

Often, the new sear release lever will need some material removed from the "foot" before the top of the lever will clear the slide.

John

Great post...and timely:

I just took delivery of a 909 and the decocker didn't work. Safety worked fine but no decock.

So I figured, "What the hell? It's just a range gun and who needs the decocker?"

Am I making a fatal error. Is there something more that can go wrong or be unsafe if the decocker is non-functional, but the safety is?

I haven't had the gun to the range yet...I just figured I'd ignore the lack of decocker. But then I read your post...tried pressing on the top sight and BINGO, it decocks. Amazing.

I don't do these sort of repairs myself...I like to trust a smith to that. So, in addition to the parts, what's an estimate of a repair. The gun is in very used shape, but that's okay, as long as it seems to work.

I've called the seller as he described it in good mechanical condition. Clearly it ain't. And I'd like to give him an estimate of the repair cost and I want to keep the gun...but be safe.

The decock function is an import part of the DA/SA system and I would not use the pistol until it works correctly.

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NHI, 10-8.

Personally, I'd seek medical help.
Denis

Has it been more than 4 hours?

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NHI, 10-8.

Thanks. I had marked the new sear with sharpie where the old one overlapped it. I took a significant amount of that off, and was able to get the gun together. Though it still required pushing down on the lever with a punch and pushing the slide back fairly hard. It now decocks with a 0.122" punch in the way of the safety, so time to buy the pin gauges.

So, I have a 5906. Purchased used from GunBroker, so I don't know when or why the decocker isn't working. But looking at your tutorial, was the bad park broken? wrong part to begin with? Someone tried to improve the function, or did it just wear out with use? If you have it handy, could you show used part and fitted part side by side?
Thanks,
rr

No the bad part was not broken merely worn out or improperly fitted. A picture of a fitted part compared to used part won't do you any good. Two reasons, the difference is minuscule measured in thousandths of an inch and you wont be able to discern that in a picture and secondly these are individually fitted parts unique to each gun. The pic closest to what you ask for is up in the first post where the bad part is stacked atop a new unfitted replacement to illustrate the difference.

To your 5906... I can't say why your gun is misbehaving without examining it firsthand. There are a number of things that can contribute to or cause this malfunction among them: a lot of wear in the slide/frame fit resulting in excessive vertical play at the rear, Improper polishing or modification of the decocker body, wear or damage to the sear, and wear or improper fitment of the sear release lever, or even a combination of more than one of those. Could even be your sear release lever is missing

I don't how long ago you got the thing but...Did the seller on Gunbroker note in the listing the the gun was broken?

Anyway I'd suspect your sear release lever is the culprit assuming of course nothing else is out of order with the weapon. It's a relatively easy fix with the proper tools albeit rather tedious. And of course you need to know what you're doing

Cheers
Bill

__________________
Because they don't make a .46

>I don't how long ago you got the thing but...Did the seller on >Gunbroker note in the listing the the gun was broken?

Gun was listed in like new condition, when I contacted the seller and explained the problem in detail, I never heard back, left a bad review.

As a side rant, I'm done with the broker, last 4 guns I got from there where listed as in good condition. All of them had easy to see issues, unable to unable to extract, unable to feed, decoker not work, unable to cycle.

My 4509 problem seems fairly "common" won't decock, decock if top and bottom squeezed together. Right decocker will, left decocker won't. It's at my smith's shop, I'll make sure to show him this article also...

Thanks

Those comments make it seem rather as if the sear release lever has become too worn and needs to be replaced - or - someone has replaced the manual safety assembly in that gun (for whatever reason) and the sear release lever is no longer within proper spec for the "new" safety assembly.

From my experience and what I've encountered, the reason the right side lever will still decock, but not the left side lever, is because the sear release lever is on the right side of the frame, under the right end of the manual safety body, and the right lever has more mechanical advantage to fully depress the lever that's become worn down. (There's a little bit of normal clearance between the manual safety body and the slide, and pushing down on the right side lever (and therefore the right end of the safety body's cylinder) might be just enough to still let the safety body push down against a worn sear release lever.)

The reason "squeezing" the slide down onto the frame will work is also often indicative of a worn sear release lever, including one whose top surface has become worn over time. Pushing the slide down in effect lowers the manual safety body closer to the frame, against the top of the sear release lever. It might help compensate for a lever whose top has become worn down. (The top of the lever is not an adjustment spot, nor ought it to be filed. Only the bottom of the lever's "foot" is filed to fit the needs of the particular gun.)

__________________
Ret LE Firearms inst & armorer

just fixed my 915 ..wanted to thank you so much for the help and photos and detailed how to..

S&W should make you an authorized armorer and continue to produce a modest amount of parts. Let you train a few of their admirers and keep these weapons maintained. Even with your excellent pictures and explanations I know is screw up anything other than the most basic maintenance.

Well, ... you just sell off that S&W junk and buy a piece of Glock perfection.