A blast from the past.
I didn't become interested in the P99's or SW99's until I attended my first SW99/P99 armorer class (taught by S&W, during their Strategic Alliance days of partnering with Walther to import the 99's into the US). Yes, we were told that the frame and all frame parts were shipped from Walther, and S&W made the slide and barrel for their licensed versions. There were some minor variations S&W requested for their frames. Of the top of my head, they included: no grip tang hook (S&W engineers felt it might push into the nerve in the web of shooter hands); Relief cut at front of grip frame, to allow shooters to more easily catch buttplate foot to remove a stuck magazine; different angle of relief in side of frame approaching mag catch levers; different accessory rail design; different texturing on frame. Might be more, but it was too many years ago and my notes are in one of the bins stored in the garage.
S&W did give some input into an issue which had puzzled P99 .40 shooters, though. Early SW9940's (full-size anti-stress models) and P99 AS .40's had occasionally exhibited early slide lock, meaning slide-lock engagement with rounds remaining in the magazine. We were told in one of our armorer classes that S&W engineers, using their high-speed imaging, had eventually observed that the top rounds, as the double stack rounds began to merge into single stack, could sometimes experience excessive lateral 'wiggle' of the cartridge noses, and this could sometimes result in a bullet nose bumping the inside tab of the slide-stop lever, lifting it enough to engage the slide stop lever into the slide's stop notch and lock the slide back.
S&W sent the information to Walther, and Walther worked with Mec-Gar to revise the magazine body and follower design of the .40 mags. The L/side of the mag body was revised to keep the rising rounds from wiggling too far to the left as they passed the mag body's mag catch cut, and nor bump the slide stop lever's tab.
Here's a pic showing a couple vintages of the .40 mags supplied with SW9940's & SW990L40's. The mag on the RIGHT is the original version, and the mag on the LEFT is the revised design to address early slide-lock. You can see the large area pressed into the mag to limit any leftward movement of rounds as they rose past the slide stop tab. Also, the revised followers (formed to fit the new mag body shape) were made darker orange to identify them (if I remember right, the Walther P99 40 mags changed from a lighter blue to a darker blue for the same reason).
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During this time S&W also requested a longer and stronger slide stop lever wire spring, with an open, hooked end. The Walther version of the spring was shorter because it had a closed, rounded end. The only downside to the open/hooked end I ever saw was how easily someone might snag the hook and bend the spring, if they were being inattentive during cleaning.
A couple other interesting changes introduced by S&W engineers in their licensed models ...
S&W engineers made some ongoing revisions to the barrels they made. Crowns, feed ramps, chamber mouths, etc. One of the interesting changes was to incorporate a flat relief cut on the bottom of the barrel. This was done to allow some extra clearance between the bottom of the barrel and the top of the recoil spring's coils. Ever hear that 'scrunchy' sound while hand-cycling another make of plastic pistol, and see some rub marks on the bottom of the barrel (from the outside of the recoil spring coils)? The relief cut was said to relieve some of it during the barrel dropping during cycling. (I later saw that Walther was shipping their own barrels with that sort of relief cut.)
Here are 4 barrels of SW9940's. The 2 on the right are original versions, and the 2 on the left are revised, incorporating the relief cut about the recoil spring.
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A couple more original, used barrels, and then a new, revised barrel.
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The extractor spring was changed from the original spring to the heavier 'optional' spring (which is the same spring used in the mag catch assembly, BTW). As I recall, it started in the S&W .40 models, and then standardized across the rest of the models just about the time the original anti-stress (DA/SA) 99 version was being discontinued in favor of the 990L. It gave some increased spring tension for the extractor, which was felt needed in the heavier recoiling .40 models, but also worked well in the 9/.45 models.
The 990L was basically the same as the Walther Quick Action (QA), but unlike the Walther model, S&W didn't incorporate the reduced size field-stripping button in the top of the slide, to decock the striker. That require having to pull the trigger on an EMPTY pistol in order to field-strip it (like a competitive model). Weird, but there it was.
Well, there was also that short production run SW99NJ model, which was made specifically at the request of the NJSP, and was basically the standard AS (DA/SA) model, but made without a decocking button in the slide. Again, weird.
At one point S&W sent out a notice to armorers to reverse the orientation of the extractor spring in the slide. The extractor (and mag catch) spring is a 'tornado' shaped spring, larger at one end. Walther originally had the wide end of the spring snugged tightly fitted into the hole in the slide. S&W decided to have armorers reverse the spring so the smaller end went into the hole. That meant it took a little more attention to keep the spring properly indexed in the hole, under the extractor during installation, but we were told that it helped eliminate the potential for not fully seating the wide end fully down into the bottom of the spring hole (which might cause extraction issues).
A couple of our folks brought in a couple 99-series guns for failures-to-extract, a SW999 (full-size 9 AS) and P99 9mm Titanium AS (titanium nitride finished slide). Both had the original (9mm) extractor springs. No problems observed with the extractors, so after a call to the factory (to make sure not other revisions had occurred between armorer classes), at the recommendation of the factory I replaced both extractor springs with the heavier optional springs. Both guns immediately functioned/extracted normally.
I've only seen upwards of 55 to 60-odd SW99's come through our agency range. Most were long term T&E issued weapons, and some personally-owned models. The highest round counts I remember were upwards of 60K-plus in a couple of them.
I think I recall 3 of them having to have new sear housing blocks installed, due to broken ejectors (molded into the plastic blocks). 1 was in a gun as it was nearing 60K rounds. Another was in a gun used as a private owner/instructor's class loaner, after some thousands of rounds, except that one had the wrong caliber ejector installed in it from the factory, so it's not surprising it might've been a stress-related breakage. The other one? Dunno why. Sometimes a part may just fail.
I still own a couple of the early SW99's, a full-size in .40 (SW9940) and a compact in 9 (SW999C). Both have seen some thousands of rounds of a variety of ammo we issued or approved over the course of time. I've put a few tens of thousands of rounds through a combination of my personal SW9940, and an issued SW9940, and the occasional SW9940 that ended up in the range inventory. I think my little SW999C is probably approaching 20K. It had an initial light-strike in DA issue, but after talking it over with the (only) Walther America armorer (S&W's Walther America company, back then), I adjusted the trigger bar guide in the sear housing block, to release the striker a little later in the DA trigger pull.
Walther was making their own revisions in the 99's throughout the years. The sear housing blocks changed, which involved a change to the inside of the frames. They also changed from using a trigger bar guide post to incorporating an adjustable trigger bar guide lever (screw adjustment). This moved the 'guide' from the bottom of the R/F of the housing block to the outside r/side of the block (one of the reasons for a frame revision). The sear housing blocks are NOT interchangeable in frames that use the different trigger bar guide designs.
Here's a pic of some different sear housing blocks for the older SW99/P99's.
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The red circles are showing the trigger bar guide posts (made for another thread), but you can see the way the dimensions changed in the width of part of the blocks, and the difference in one of the tube pins. In this case, replacing an older block with a new one, of the revised design, required replacing the pin in the new block with the pin from the old block, which isn't something they were teaching to armorers (but which the factory tech explained to me). As a matter of fact, Walther didn't want armorers to disassemble the sear housing blocks at all. It was restricted to factory repair. Except ... shipping the assembled blocks sometimes resulted in the blind sear lever pin to fall out of the block, freeing levers and a spring, so the class taught armorers how to reassemble blocks they received as repair parts if they disassembled themselves in-transit. BTDT.
I only went through 3 of the armorer classes for the 99's back then, and I'm probably forgetting some of the things from my notes in those classes (and not mentioning other things that may not interest folks in this thread).
I rather liked the 99 AS series, no matter who sold them. I was sorry to see the SW99, and then many years later, the P99 AS apparently discontinued.
I never cared for the QA or 990L, myself. I never had a chance to handle the original 990 DAO.
From what I understand, since S&W shipped all of their remaining Walther parts to the new Walther company, S&W no longer does any warranty repair for the SW99/990L's. Dunno if the new Walther Arms company would work on a SW99/990L, since that's an obsolete model from another company (even though the frame and frame parts were supplied by Walther). What the hell, though, right? Walther announced they're discontinuing their PPQ, so now the P99 and the PPQ are passing into history. I ordered and put away enough parts to hopefully keep my own SW99's running for the rest of my life. The good news is that they didn't seem to need much in the way of replacement/repair parts during the years I supported some as an armorer.
Just some thoughts.
