Question for Fastbolt or other 3rd Generation Experts

[capnkirk]

A friend gave me some S&W 3rd generation disconnectors. I am replacing a missing disconnector in a project gun. I have 3 different types of disconnectors. The first type is a one piece plastic part, the second type is a one piece metal part, and the last is a metal part with a cylindrical pin driven through the end which engages the drawbar. Are these parts all interchangeable? Which is the oldest type and can you tell me anything about the evolution of 3rd generation disconnectors? Thanks, Capnkirk

[Jhp147]

I am not any form of expert, but have been to the armorer's class at the factory. The plastic (S&W says nylon) was the most recently manufactured form I have seen, probably started with the TSW guns. I have not seen the 2nd generation gun's insides so maybe the one with the pin driven in is from them, I only recall one piece metal ones in the earlier 3rd generation guns. Dont know for certain about interchangeability, but you can try to match it based on if the gun's place in the changes.

[Fastbolt]

I actually sent some info to the gentleman posting offline, so it never made it into the forum thread ...

The disconnectors you listed are from different time/production periods. The plastic (nylon) one is the newest, with the solid cast steel part being in the middle and the stamped part with the pin being the oldest. I'm not certain, but I think the pinned part ran up into the high 2-digit models or maybe even the early 3-digit models. (Added: I didn't start working as an armorer until the 3rd gen guns had been in production for a few years, and aside from the 3rd gen guns, pretty much only had call to help service the occasional late 2nd gen [3-digit] guns. Maybe someone else might have some better info on the older guns, since my "pre-3rd gen" armorer manual is out in a bookcase by the bench.)

The plastic part is the easiest to use. It has the advantages of being the most consistent in size/dimensions and having least amount of friction/resistance against the disconnector tab in the center of the drawbar. While the tail can be broken off, it's just about always caused by improper removal/installation. If too much pressure is exerted against the tail when trying to move it around the drawbar tab (to remove/install it, using a pin punch to push against the tail) the tail can snap off. It's not something I've ever heard of happening during actual functioning when the gun is assembled and being fired, though. It's inattentive and less experienced armorers who can break them.

Also, the consistency of the plastic parts means the occasional (seldom?) problem of a "long tail disconnector" isn't even something listed as a potential problem in the newer armorer manuals any more. Older steel disconnectors might sometimes have a tail that could prove to be too long in an occasional gun, causing a Skips-Double Action problem which would require the tail to be carefully stoned and shortened. However, improperly filing (stoning or polishing) the part can create its own problems. A worn (improperly shortened?) disconnector can create a condition where the gun might fire even when in 1/4" out-of-battery, for example.

The reduced friction & "lubricity" of the plastic part's tail makes for a smoother contact between the part and the drawbar's tab, too.

I've installed the newer plastic parts in my own guns to get the benefits of the better tolerances and smoother operation.

As I recall, in my first armorer class for the 3rd gen's we were told that extended factory testing had revealed that the plastic disconnectors equaled the durability and performance of the steel parts, and had actually been considered to have exceeded them in some respects. The only discussion I've sometimes heard offered for bringing back the steel/cast part is to maybe reduce the potential for an assembler, technician or armorer to get distracted and maybe snap off a tail when rushing through assembly/disassembly, not because the steel part is "better" in actual usage.

The steel parts are fine in most guns. I've still got a bunch of them, as well as a few plastic ones.

If it were me, I'd save the older stamped/pinned part for a curiosity in a parts drawer, and use the plastic or solid steel part. As long as the tail isn't too long, pushing the drawbar too low and causing a Skips-DA problem (making you think your hammer & drawbar are worn at the Pick-up and throw notches on both parts, causing you to needlessly replace them), the steel parts are durable and fine.

The plastic parts are nicely sized and well-made, and offer the benefits of a "polished & smooth" part without having to fiddle with them. Just be careful not to break off the tail while installing or removing one (trying to force it around the drawbar tab).

I've also seen a new armorer install the disconnector backwards (that was a new one on me), and that meant the tail was sticking out (forward) into the mag well. Naturally, the tail blocked a magazine from going into the gun. A plastic part would have probably ended up having the tail snapped off right away when the empty mag was inserted to do some bench checks. First time I ever saw someone do that before ...

[Jhp147]

Hello, FB, should have figured you had taken care of him, glad my estimates are close to right on period/part. I just found some old info from you on these things but at that time you didn't mention the funny one with the metal pins, I just figured it was older, before they could cast more complicated parts with 90 degree angles. You had mentioned that the plastic ones appeared to do a much better job because of consistency.

[Fastbolt]

How 'ya doing Jhp147?

I had to call a retired armorer to ask about the stamped part with the pin crosspiece. It pre-dates my time working with them, and I don't see many older 1st/2nd guns for support. (Then again, I'm still waiting to come across a certain type of sear spring from an older M39 to add to my collection of interesting parts. I found some of the 1076 frame decocker/hammer parts a few years ago.)

I had pretty much the same initial reluctance as many other folks when first seeing the plastic parts in the later production 3rd gen guns (disconnector & mainspring plunger, for example), but once I saw they were indeed serving fine in the newer guns I gave more credence to the factory's claims of the same, or even superior, service life and performance.

I remember an armorer recert class where the instructor claimed he wasn't familiar with the 'long tail' problem that could occur with an occasional older steel disconnector, and how the disconnector might require careful adjustment (although I'd sooner replace it with another one if I had one, if only to save time). I had to bring in an older 3rd gen armorer manual the next day to show him.

[WR Moore]

While working on a slew of model 39's, I once asked S&W why the ejector (disconnector) plunger was made out of nylon and the response was that it outlived the metal version while reducing wear on the ejector & slide. Which would probably be minimal anyway.

While I have to admit I view the nylon disconnect with some concern, I have to conceed it's a low stress part in the S&W design and (probably) shouldn't be an issue. Heck, I've got a Nylon 66 that used the Nylon for the receiver.

[Fastbolt]

Yeah, seeing plastic parts in steel guns can sometimes be a bit disconcerting the first time you notice it.

Then again, now we have plastic-framed guns.

The only time I've had to replace the ejector depressor plunger in a slide was when an older ejector had the tip break off, and the resulting jagged stub was digging into the plunger, badly gouging it.

Otherwise, they seem to last, don't they?