I just received a 6906 LE trade in from CDNN and was very pleased with the condition.....not beat up at all and seems to have not been fired much. Anyways, she was quite filthy and had not been cleaned after previous firing so I pulled the grip, field stripped and gave it a nice cleaning and light lube. I took it to the range and accuracy was very acceptable however then the issues started......after every mag is empty the slide does not lock open. Its a LE stainless mag that came with the gun....is this a mag issue? Next problem, on the second mag the slide failed to cycle completely, it stripped the round from the mag, loaded it into the breech but did not lock forward completely and seemed to "jam" or "stick".....I dropped the mag, pulled the slide back and ejected the round which "looked" ok. I reloaded and started again and after 5-6 rounds it happened again, slide "stuck" in the half load position....what is causing this? Mag issue related to the last round non lock open or is this two problems? Maybe a weak recoil spring? Anybody have any ideas? TIA....

PROBLEM SOLVED!!! Got the pistol back from S&W yesterday......took about 3 weeks as they indicated. Apparently the "adjusted" the extractor to factory spec and "adjusted" the slide stop to spec and test fired....total cost = $zero. Anyways, took her to the range tonight and ran 100rds thru her with zero malfunctions......all good. Gotta love S&W service.....

Having blasted thousands of rounds through my 6906 over the years, and NEVER having literally any issues whatsoever, I have to wonder if the mags might be the first place to look. I'm not familiar with whatever LE mags those might be, but my factory stainless 12-cap ones have been flawless. On top of that, I've never changed a single spring in the gun or the mags, and again, never have feeding or ejection issues.

So, check the mags, first, then look to the recoil spring if need be.

It does sound like it could be a mag issue. I would replace the magazine spring. With any used, especially police trade-in gun, I always replace the recoil spring and magazine spring(s) by default no matter how clean or new the gun may look.

I agree get new mag spring from wolf as well as a recoil spring.

Sounds like sage advice to me.

Worn follower not allowing the lobe of the slide stop to trip into lock back...another possibility.

Colt, I doubt the worn follower since the gun shows hardly any wear.....I may try another few rounds thru it to see if it reoccurs and if it does I'll swap in one of my 669 or 5906 mags to see what happens....if its the mag I'll just change out both springs as suggested...wheres the best place to get the Wolff springs?

From Wolff springs.

Springs for SMITH & WESSON NUMBERED SERIES Semi-Auto Pistols

For Use in:
469, 669, 6904, 6906, 6924, 6926, 6944, 6946, 9mm
411,4003,4004, 4006,4026,4043,4044,4046, .40 S&W

As has already been mentioned, the first thing I'd do is replace the recoil and mag springs. Factory springs are fine. (For a while I used Wolff +5% mag springs in a couple of issued 6906's I carried, with factory recoil springs.)

The factory recommendation to armorers for recoil & mag spring replacement used to be based on free length of the springs compared to new ones, but then the company simplified their recommendation by telling armorers to replace recoil & mag springs either every 5 years of use (pretty much meaning mags left fully loaded in LE guns), or every 5,000 rounds fired, whichever came first.

I've seen mags dropped onto hard surfaces (concrete) by cops now and again, and it's not impossible that a "used" mag might have an issue with the lips. New magazines are costly, but a good investment.

Followers can eventually develop a deformation where the lip of the last round digs into the follower under recoil. If that spot gets too rough it might interfere with feeding of the last round, but I've seen them take a lot of abuse and keep feeding normally. I've been reminded by the factory that the black followers used in the 6906 are slightly different than the black ones used in the older 59XX mags (due to the increased slide velocity in the shorter 669/6906 guns and how it can affect feeding). I never could see the subtle differences by eye, but I believed them and kept them separate from those used in the older 59XX mags.

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Ret LE Firearms inst & armorer

ColColt and Fastbolt are right about checking the mag follower. A friend of mine and me both bought 6906s that were ex CDC guns and we got 2 mags with each one. They all had some wear, but one had a rough worn follower and it consistently did not lock his slide back on the last round. That mag in my gun worked ok most of the time. If you look closely you will see that a groove has been worn where the lever on the slide lock hits the follower. Hope that helps. BTW I bought mine in the fall and have really enjoyed the gun. They are a nice weight and size.

Nope.......its not the mags or the recoil springs.....I switched mags with my 669 and 5906 and the slide was still was not locking fully forward after firing....I also switched the guide rod and spring from my 669 with same results....after firing it will move the slide forward about 85% and then "sticks/jams"...with a slight push on the rear of the slide it will lock into position but I feel a slight resistance like a burr or something but I've checked slide,barrel and frame and see nothing...maybe a trip back to S&W is in order?

you could try a +10% recoil spring. give it some more umph

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6906,6904,g23,g21,RIA1911,40c

If the round enters the chamber ahead of the extractor and fails to go to battery that's a mag problem, pure and simple especially if the slide lacks about 1/4" going into battery. That slight resistance could be the extractor claw trying to cam over the rim as your pushing the slide forward.

An extractor problem may be the culprit. Out of the five S&W used semi-autos ive purchased only one-a 5906-had a problem, and it was the extractor. Upon acceptance my 5906 had two compound failures every magazine. Looked something like this:



After a new recoil spring, the gun would malfunction at random. Bought a new factory magazine , and with the changed parts the weapon went 90 rounds...and did this from rounds 93, 96, and 99 out of 100:







Id send it in to the factory with a picture & written description of the problem. The price to repair it will run something close to $100 give or take.

Colt,
I've switched mags and its still doing it with my 5906 and 669 mags ALTHOUGH it wont lock slide back on the factory mag it came with but WILL lock back with my 669 and 5906 mags....there is a slight groove worn into the follower on the factory mag.....

Look at the little lobe on the slide stop that penetrates the frame. That's what triggers the slide to lock back when the follower rises up to activate it. See if anything looks odd or out of the ordinary about it...a burr on the edge for instance being too long could do it but I wouldn't' think that's likely as the problems seems sporadic. I'm certainly no gunsmith but I feel your pain as I've experience my fair share of pistol problems...fortunately not very many of the 3rd Gen models but others.

Silver, did the extractor/spring replacement fix your problem? Which was it?

Colt,
I know what you mean.....it bugs the absolute **** out of me owning a gun I cant trust my life on if the need arises....

Are you sure you cleaned out the channels and slots for all the dingus-levers?

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WWSSD?
What would Skeeter do?

I got one of those and had to literally drown mine in break free to get it in working order.Evidently these came from some desert area because there was sand in every crack and crevice.It is now 100% after it's breakfree bath,200 rounds down range without a hiccup using the LE mag it came with.

The gun needs to be checked by a gunsmith familiar with S&W pistols, a S&W armorer or the factory. You may have a couple of things going on at the same time. That can make diagnosis a bit tricky, and requires someone knowledgeable in the guns to examine it in person and identify the problem(s) that may exist.

Some thoughts on what has been posted so far in this thread ...

The failure-to-lock back on an empty mag ...

If the other mags are letting the slide lock back when they run empty, but the one that came with the gun isn't, it's possible the mag spring and/or follower that came with the used 'factory' mag need to be replaced. (Not a bad idea anytime a used mag is involved, anyway).

The erratic and inconsistent feeding ...

Failures-to-feed are typically caused by the ammunition; the magazine(s); a dirty chamber; a damaged extractor; a barrel with an overly long tab (rear of hood); or a recoil spring.

Are the frame rails in good condition, or did someone run the gun too long without sufficient lubrication?

While a failure-to-extract can be caused by a damaged extractor and/or a damaged or weakened extractor spring, a failure-to-feed may be caused by a problem at the "other end" of the extractor.

For example, maybe there's excessive gunk, fouling or even some bit of debris that's accumulated under the extractor tail, or within the spring, preventing the tail from pivoting inward and letting the hook move outward as intended during feeding. This can create problems with feeding "timing".

Former LE gun, right? No way to know how it was maintained or repaired (if necessary). If the extractor required replacement at some point, was the extractor fitted correctly? If it was over-filed and is too tight, you can get feeding failures. Was the correct extractor spring used if it was replaced? Too heavy and you can get feeding failures (because the extractor has too much tension). These issues can become complicated by unexpected ammunition tolerances might vary when it comes to case diameter or rim thickness.

Was the barrel replaced at some point? If so, was the tab checked for fit? Too long?

Are the frame camming surfaces in good condition? (Those are the angled surfaces in the frame, to each side of the barrel's feedramp, where the barrel lugs run up & down during cycling.) Are the top points of the those angled surfaces in the frame still within proper spec, so the barrel is release to return up and into battery correctly? It's critical that the top of them are in good condition for proper feeding & functioning. Some peening can normally occur in the 'middle' of the camming surfaces (alloy frames can experience more wear from the steel barrel lugs running up & down them than when a steel frame is involved), but if the top surfaces are damaged the frame is generally not salvageable. (I once had a 6906 alloy frame get pretty peened and worn in the middle of the frame cam surfaces as the round count was approaching over 40K rounds, but the top 'release points' were still good and the gun was running reliably.) This is something I'd leave to the factory to determine, myself.

It can become understandably frustrating to have one or more problems interfering with the normal operation of a gun. Especially one as normally reliable as the 3rd gen guns. However, guesswork can only make things more frustrating, and 'trial & error' attempts by someone not trained with diagnosing and correcting simple problems can make things even more frustrating. Not to mention maybe creating further problems.

Why not call the factory and inquire about having the feeding problem in a former LE trade-in gun be examined and corrected?

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Ret LE Firearms inst & armorer

Excellent advice and that's what I would do in the OP's case. I just acquired a well kept 4516-1 and all I did after the initial cleanup and lube was to replace the recoil spring, mag springs and followers. It's been a delight. I ordered the service pack from Wolff that includes about every spring this pistol will ever need...ditto for the 4506, come to think of it.

If you don't mind my offering a couple of thoughts, I've used an assortment of the Wolff springs for the 3rd gen guns over the years. They make a fine product. Good folks, too.

The slightly reduced power hammer(main) springs can lighten (and seemingly 'smooth out') the DA trigger, but bear in mind they're lighter than factory springs, and heavy primers are out there.

I'm no longer interested in trying to use their reduced power drawbar springs (trigger return spring) for dedicated carry 3rd gen's. Not since I tried one for a while and started experiencing a "Skips DA" condition due to the weak spring force. (Granted, their website is quite clear in stating that these springs are for competition guns only, and aren't intended for duty guns.)

They're a source for the older single recoil springs for the older 4516/4516-1's, but they also recommend calling them before ordering to discuss it.

I've used their mag springs for 1911's & double stack 3rd gen's with great success and satisfaction, but I prefer the "factory" (still a vendor ) 3rd gen .45 & 9mm single stack mag springs ... and factory recoil springs. (Except for the SW1911's, in which I use the Wolff mag +10% springs for the ACT-MAG's, and recoil springs. I thought I remembered hearing one time that Wolff was supplying S&W with the recoil springs for the SW1911's ... but I could be wrong, or things might have changed.) Anyway, I like the longer "factory" .45 3rd gen spring with its more coil windings.

I've sometimes used their extra power firing pin spring, especially when running a lot of +P+ loads in an occasional 9mm (if I start to see some noticeable pin wipe). No complaints.

I only use factory extractor springs for 3rd gen repairs. They have a wide range of extractor springs that allow a gunsmith, tech or armorer to fine-tune any particular gun, which can be handy, especially when dealing with older guns made using older equipment and production methods. The "weight" of the spring is different than than the amount of tension (in pounds) exhibited when checking an extractor & spring using the force dial gauge, anyway.

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Ret LE Firearms inst & armorer

I think the hammer spring is standard. I didn't want any reduced power springs of any sort. I'm debating changing out the hammer spring but there's no problem with the one that's in te pistol I thought of changing it just because I don't know how old the pistol is...1999, 2000? SN is TED3XXX. Nor do I know if any spring has ever been changed so the recoil spring was the first to go and then the mag spring. I ordered two extra mags but also have Wolff replacement springs for them as well. One came with the service pack.

There's a lot of little tiny springs that I have no idea what they're for but if I ever decide to delve into a complete take down, I'll match old with new just to be sure what fits where.

This is what comes with the service pack on a given pistol, I got the Type II...

Service Paks

TYPE I - For Smith & Wesson semiautomatic pistols contains the following springs to replace weakened or broken springs, returning the pistol to original factory condition: recoil spring, extra power firing pin spring, hammer spring, extractor spring, 2 ejector springs, magazine catch spring, drawbar plunger spring, safety lever plunger spring, slide lock plunger spring, safety lever detent spring and rear sight body plunger spring.

TYPE II - contains all springs described in Type I pak above and a +5% extra power magazine spring.

What do you mean by "light lube"?

"Light lube" = a small drop of remoil on each slide rail, hammer pivot and trigger group...........reassemble, rack by hand a few times, wipe of any excess under rails or around trigger group, reload and holster.

Excessive and insufficient lubrication can both cause problems.

Excessive amounts can allow it to run under gravity and migrate to areas where it shouldn't go. Places where it might become stuck and attract an accumulation of fouling, dirt & debris, which might in turn develop into a thick and nasty sludge, interfering with normal function (firing pin channel, around the frame parts & assemblies, inside the extractor recess, etc).

I've seen nasty accumulations gather around the sear, drawbar and other parts inside a frame and create functioning problems in guns. Another instructor brought me a relatively new (3-4 years old) 4566TSW in which the hammer wasn't consistently staying cocked during firing for the issued user. I disassembled the frame and found a surprising accumulation of slightly wet, sticky/tacky sludge that had gathered around the sear, preventing it from moving easily. This had apparently caused it to stick and not move fast enough to consistently catch the hammer's SA notches. (Nothing appeared to be wrong with the parts themselves.) Once clean (and NOT lubricated), the sear moved easily & normally, and the gun once again fired and operated normally. This was a user caused "problem" which had involved less-than-ideal cleaning & lubricating practices, which had allowed an excessive amount of solvent and/or lubrication to migrate around inside the frame.

Insufficient lube can also lead to problems, such as accelerated & excessive wear on the frame rails in the alloy frame guns. Slowed cycling, especially under the increasing heat of repeated firing.

When armorers do detailed inspections they can wipe down the various frame components, parts & assemblies with a lightly moistened patch, but this isn't the same thing as "oiling" the parts. Just wiping them down and then reassembling the gun. Aside from the bottom sides of the hammer, the rest of the frame parts & assemblies aren't normally "lubricated" when the guns are field-stripped for normal cleaning.

The use of one of the good quality synthetic greases made for use on firearms is also fine, as long it's applied according to the manufacturer's directions. Some of them are thicker and don't easily spread, and have to be put where you want them to be (fingers, Q-tips, other applicators, etc), and some are thinner and will spread a bit better. Read the directions.

I like some of the greases for conditions where the gun may be exposed to constant temperature changes and humidity (like near bodies of water), and they'll probably remain on the gun longer than some of the oils (which can have their carrier base evaporate, run off and thin under gravity or be wicked away by holster linings). Just depends.

I usually have 2-3 good synthetic greases and at least that many different synthetic oils that I use. Some make for easier cleaning after shooting, and some not so much.

Now, S&W 3rd gen armorers are given a pretty basic recommendation for lubrication. (For 'normal' conditions, although some different operating environments might necessitate something different.)

One (1) drop of oil on the barrel (especially at the muzzle)

One drop on the barrel hood (front of the hood, where it meets the front of the ejection port)

A drop each on the left & right rails of the slide (or frame). (I usually put 1-2 drops on the tops & sides of the front of the frame rails, where the slide rails will spread and carry it as I install the slide.)

On drop on each side of the hammer (at the bottom, where it rubs within the frame, but not so much that it will run off under gravity and migrate away from the hammer).

It's not a bad idea to rub some oil on the guide rod, too, and the oil remaining on your fingertips after rubbing it around the barrel/muzzle is probably enough to lubricate the guide rod.

The .45 frame rails aren't broken up into the same sort of shorter rail areas as on the of 9/.40 frames, so I usually use a bit more oil (or grease) on the .45's due to the added frame rail surface area.

I like to be able to see the frame rails exhibit some light degree of visible wetness (top & "upper" sides of the front & rear of the rails, and along the "lower" outside part of the rails). The places that can start to exhibit wear marks from cycling. If someone is having sluggish cycling or feeding stoppages on the firing line, and I fields-trip the pistol, I usually see dry rails. A couple drops of oil usually restores then gun to normal function in those sort of instances. (Another gun maker recommends their owners/users clean & lubricate the guns when new (before firing), after each time they're fired, or monthly (fired or not), whichever is applicable ... which ought to make sure the guns don't run dry, huh? )

Now, the presence of lubrication can also act to help mitigate the vibration & shock which occurs during firing, helping to spare the metal from the vibration. (This was discovered by another company who makes allow-framed service pistols. I was forwarded a warning issued by one large agency using that company's weapons, and came across a wall poster in another agency using those weapons, on which someone had written in marker ink "lubricate your guns or die". Subtle, huh?

Just some rambling thoughts about lube. I'm not an expert. I don't shill or specifically push different oils & greases. The market has a bunch of good ones made for use on firearms. Pick whatever suits your fancy, and/or any specific conditions anticipated. Read the directions, though. (Hey, some folks still use old-fashioned Gun Oil from cleaning kits, or even 3-in-One Multi-Purpose Oil. )

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Ret LE Firearms inst & armorer

Remoil works ok on my Remington bolt actions but it has done nothing but cause problems on my SS 3rd gen pistols. Break Free works or one of the gun greases like Slide Glide.

If the slide doesn't lock back after the last shot are you are unable to find any mechanical reason for it, perhaps you are shooting "high thumbs" and are riding the slide stop. I suggest this because I have done it with my 669.

I'm probably guilty of putting too much on one...too many 1911's from the past I guess. I like to put some Gun Butter grease on the locking lugs and use FP-10 everywhere I see a rub mark-especially the rails, a drop on the disconnector, barrel and hood and around the barrel bushing. I stopped using Break Free CLP as it just goes away in no time...sort of like evaporates.

Koz,
it isnt my shooting style......I carry a 669 every day and shoot it about once every 2 weeks with no issues.....I also carry a G19 outside the US and have had no issues with it or the CZ 75 and variants.....its definitely a mechanical issue....just waiting on the return slip from S&W so I'll let the experts figure it out...