This is the second one in a row I've gotten like this. You can see where the steel fractured and there's a good size chunk of steel missing. That absent piece took the rear half of the ejector depressor plunger track with it. The plunger hangs low beneath the slide, cocked slightly to the rear and drags on the frame. There's no way I'd run it like this for fear it would outright fail and tie up the gun.

I know I can pull the plunger and run it without the magazine disconnect, I'm just not inclined to disable a safety feature. Plus just knowing something is broken in there would make my brain itch.

This one I got about a year ago.


I got the second one few months back off GB. Tore it down today and found the same break.

I'm now really curious if any of you 3rd gen wizards or armorer types have seen this particular damage before and how common you think might it be? And, please feel free to offer opinions of what may have caused this.

Could this be a factory defect that got by QC perhaps? Judging by the mess of toolmarks in there I could see a milling cutter get to chattering and taking out a chunk of steel like that.

I was going to use one of these for my SSV project but that's on hold for now.


Cheers
Bill

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Because they don't make a .46

Freaky looking, huh?

Yeah, I called back in a mild panic to discuss it with a tech the first time I saw this on a brand new 4513TSW. (I was inspecting a gun from a new shipment of .45's and saw this on one of the 4513TSW's.)

I was told that the "break" was actually intentional, and had just started being done to relieve a thin spot in the ejector depressor plunger channel (at the rear), next to where it intersects with the firing pin channel cut.

It was further explained that the shape of the nylon plunger, with its added side ribs, resulted in this thin spot where the plunger's rear rib needed to move up & down freely. Not much steel behind that cut for the plunger's rib to move within. (The round firing pin safety plunger on the other side of the firing pin channel doesn't have an added "rib" protruding to each side, so the plunger channel cut is thicker in the corresponding spot at the rear of that cut.).

The engineers had apparently observed that this thin spot could sometimes eventually crack under recoil. I was told that it's not a critical spot for the crack to form, with the rest of the plunger being normally supported within its recessed cut. (Note the way the plunger tip is contained within the rest of the normal machine cuts. It's not as "unsupported" as it may appear at first glance. The "rubbing" or "drag" marks on the bottom of the plunger are commonly caused by the ejector's movement underneath the plunger, some of which have some variable smoothness along the edges.)

Rather than leave it to normal wear & tear to eventually "break" the thin metal from the intersecting machine cuts, though, they decided to start knocking out the metal where the crack could form. Pre-breaking it, so to speak.

This bit of newer machining to relieve the stress in the thin part of the slide at that spot isn't even really a cosmetic issue, as the manual safety assembly has to be removed in order for it to be revealed. (As you've discovered. )

After my conversation with the factory I checked a couple other new production 4513TSW's received, and sure enough, I found the new guns had the same "break" and "missing" piece of metal.

I was also told that this machining step was planned for the rest of the new TSW guns as production continued.

This isn't the first time something like this has occurred, BTW.

One side of the disconnector cut in the bottom of the slide is thinner than the other side due to machining and an intersection of cuts. It often (eventually) resulted in a thin triangular steel "flake" breaking loose under recoil. I was told that it usually fell free of the slide during cycling, which let it fall free of the gun without the shooter even knowing it happened. (This triangular spot on one side of the disconnector notch is now "open" on newer production slides, as newer manufacturing methods can remove it.)

The rear of the thin machined cut underneath the extractor recess, on the right side of the pick-up rail in older 9/.40 slides, could sometimes develop a curved crack, running from the end of the cut to the side of the long channel along the right side of the pick-up rail. The metal connecting the "top" of the slide channel on the right side of the pick-up rail, and the bottom of the extractor recess cut above it, was VERY thin at that spot. Recoil forces could easily let the resulting thin piece of metal develop a crack, which ended as soon as the thicker metal was reached on the outside of the long channel.

Sometimes this "crack" would result in the thin piece of metal between the end of the machine cut and the edge of the long channel breaking off and falling away. It wasn't very large. Sometimes the "crack" relieved the stress and the thin "floor" of metal connecting the bottom of the extractor recess and the long channel remained in place. Not critical, but it could be a minor cosmetic surprise to an owner/user finding it during cleaning. Newer machining methods allowed them to make better cuts that eliminated the potential spot for this sort of stress riser to occur.

Another occasional spot for this sort of thing was in the front of the early 645/4506/4506-1 slides, at the rear of that thin metal tunnel connecting the barrel and the spring box. The machining of that thin metal sometimes allowed for what looked like a chunk of "missing metal", a large "crack", a break, etc. It was actually intentional, and necessary for the easy removal & installation of the barrel during field-stripping. They called it something like a “4 degree free cut”. It could look nasty, though, and still freaks out the occasional owner who notices it for the first time. Later machining methods allowed for a better bevel cut in that spot.

So, unless something's changed since my last armorer update/recert, and my conversation with the tech (close to 5 years ago) when I found the same thing and did a double take, the picture you posted looks like the other new production 4513TSW's I've seen.

Just my thoughts. Feel free to call back and try to get a tech on the phone. Don't be surprised if you hear a good-natured chuckle, and something along the lines of, "Oh, you found that, did you?"

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Ret LE Firearms inst & armorer

As always, Thanks for the info, Fastbolt!

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Lounge Lizard Extraordinaire

Hi, Bill!
I don't want to be a "me too" kind of guy, but after examining 13 slides, Fastbolt's description is right on the money.
Newer slides, produced after circa 1997, certainly display a consistency with regard to the jagged tear-out in that area.
It seemed to me the plunger was sufficiently restrained and the ejector was in no danger of catching on that edge.
I also had a feeling it was akin to the thinning in the recoil spring tunnel that Fastbolt described (cosmetic rather than dysfunctional).
But it's nice to have official verification.
And I gotta say, under "stoopid-high" magnification and resolution, that tiny fissure looks like the Grand Canyon!

John

That sure looks ugly, and it would scare the **** out of me if it were my gun. Thanks for the explanation Fastbolt. As I always do, I learned something reading your post.

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Can open, worms everywhere.

Is this an example of sloppy engineering and design? Is this type of thing common in a quality firearm? Would you expect to see this in competitive brands like Sig?

Bill

Fastbolt,

Thank you kind Sir, for taking the time to write a detailed reply.
I certainly appreciate the information and your insights,
Thanks for sharing and... thanks for alleviating my concerns.
The only reason I have to call S&W right now is to cancel the
replacement slide I've had on backorder since April (not that I
was holding my breath for it). Well, I guess I'll strap this one down
in the milling fixture and get back to what I was doing in
the first place.

Cheers
Bill

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Because they don't make a .46

1. No. This sort of thing is how the "open" cut ended up above the slide stop lever tab in some designs, FWIW. Making the cut open at the top eliminated the potential for a frame crack in some designs/models.

2. More than you'd probably think.

3. They have their own wear & recoil force related issues which may not be visible to the average owner.

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Ret LE Firearms inst & armorer

This is worthy for nomination to the notable thread index... I just sent the link to the big gorilla asking for such.

Great info as usual Fastbolt!!

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Conrad
SWCA #1830 SWHF #222

Bill, If you don't mind me asking, what are you building now? Its got to be cool if its based on a 4513TSW, & the kind of magic you can work is well known on this Forum. If its a secret I understand.

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Lounge Lizard Extraordinaire

Uh, while I appreciate the sentiment, don't make more of it than ought to be made. I just happened to have run into it a few years ago and asked about it. There are more experienced folks than I who hang out around this forum, including some smiths and at least one former S&W employee.

I'm neither an engineer, gunsmith, technician, production worker, machinist, factory rep nor anything else resembling any sort of expert. LE armorer, yes, but that's more or less something more closely akin to a plug 'n play parts replacement person.

I have no doubt that I don't know enough to really know what I don't know.

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Ret LE Firearms inst & armorer

I guess you could call it a 4566TSWSSV or maybe a 4596TSW with a little bit of Devel thrown in.

Cheers
Bill

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Because they don't make a .46

DING, DING, DING! No more calls, please, we have a winner.

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Can open, worms everywhere.

If we had a "popcorn" smiley, I'd use it now. I can't wait to see what you have planned!

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Can open, worms everywhere.

Well perhaps... but you're the one that took the time to share that info with us (and usually do)... in detail, which in my book still deserves a tip of the hat at the very least .

Anyone else reading the post will now know not to go into panic city when they encounter the same thing.

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Conrad
SWCA #1830 SWHF #222

Excuse the necro posting, however I ran into this today on one of my 457 slides. Of course I had completely forgot about this thread until Heymatt found it and posted a link.

I had a couple of light primer strikes today during a qualification shoot for a CCW permit. Fortunately, I had my 457S along and finished with that.

I figured it was gunk in the firing pin tunnel and took out the safety lever, firing pin, and spring to do a thorough cleaning. Which is when I spotted he "broken piece."

This thread relieves my anxiety and I expect that the cleaning will solve my misfire issue.

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Can open, worms everywhere.

Good info!