Three Generations Of S&W Semiautomatics

Concealed carry permit holders have the best assortment of suitable guns for this purpose available than ever before. A plethora of .380s, 9mms, .40s, and .45 semi autos have been introduced to cater to the demand of a public fed up with being disarmed and helpless in the face of vicious criminals who don’t obey laws, gun controlling or otherwise.

Back in the day, before the highcapacity 9mm revolution when revolvers ruled as defensive weapons, you had choices including all the snub-nose revolvers from Colt and S&W; about the same as the Model Tas long as it was black. Those preferring an autoloader had to be content with Colt Commanders or European Walthers and such (along with James Bond.) These guns were not bad choices, and still do the job today, but firearms evolution in America produced something a little different.

It seems along time ago but the first centerfire, self-loading pistol of double-action type designed and produced for the commercial market by an American firm was the Smith and Wesson Model 39, introduced in August 1954. In my 1964 Gun Digest the blued gun was listed for $89.00 and the nickel-plated version at $95.00. Before that, most of these types of pistols were of European manufacture, the most notable being the P38 that was made in large quantities as the official German service pistol.

Double action in these types of guns means that when the safety is released and the hammer down the gun may be cocked and fired by pulling the trigger. The subsequent shots will then be fired single action with the hammer already cocked. Also, if there is a misfire on the first shot another trigger pull will give the firing pin a second chance without having to pull back the slide to eject and replace the cartridge. I don’t know if that is a big deal.

If the piece fails to fire on the first strike, and the pistol is in proper condition, a second blow probably won’t make any difference. However, I do think this is a worthwhile safety feature, especially on a duty pistol or one being used for self defense as a cocked pistol has a much lighter trigger pull. In a tense situation a trembling trigger finger can let ‘er go bang almost as easy as blinking an eye. That’s the same reason I will not cock a double-action revolver unless I know I’m going to shoot.

Many police departments around the country agree with me and require double-action pistols. That being said, these little pistols can spit out a bunch of lead in a hurry if need be. The 39 was made with a single-stack magazine that held eight rounds and was adopted by the Illinois state police in 1967, giving a positive bounce to its popularity. In 1971, S&W responded to public demand by bringing out the same pistol with a fourteen round capacity—the Model 59.

The grip contour of the original was made straighter and the grip panels changed from walnut to a thinner nylon to accommodate the larger magazine. In 1989 the stainless steel model 5906 was introduced and became immediately popular with many law enforcement agencies. You may encounter model 39s with either an alloy or all steel frame. In 1981 the gun was designated the 439 for the standard blued version and 639 for the stainless steel version.

As a gunsmith, one of the things about these first generation pistols you should be aware of and alert your customer to is that they were manufactured with an inertial firing pin without an automatic firing pin safety plunger. This means, with the safety in the fire position, a loaded gun can discharge with a sufficient blow to the muzzle, like being dropped, for instance. A 9mm pill ricocheting around the floor is a nasty situation and the best way to instill happy feet in innocent bystanders.

The second generation pistols having three digit model numbers (439, 459, 469, 639, 659, and 645) and the four digit, third generation guns (3904, 3906, 5904, 5906, 6904, 6906, and 4506) all have an automatic firing pin safety plunger. This prevents the firing pin from moving forward unless the trigger is held to the rear. Field Stripping After making sure the gun is unloaded and the magazine removed, move the safety to the fully up "fire" position.

Pull the slide rearward until the slide stop hole in the frame is aligned with the cut in the slide to allow removal of the slide stop. The slide assembly is then withdrawn towards the front and off the frame. It is a good idea to grasp the recoil spring and slide assembly together as the spring is under tension. The spring is removed by depressing it

slightly and freeing it from the small radial undercut in the barrel lug. The barrel can be easily removed for cleaning from the breech end. This is all the disassembly necessary for field maintenance and general cleaning by the amateur owner. For a gun with feeding problems, broken or worn parts to be replaced and for a gun that has been fired extensively that can use a good cleaning, a more thorough take down is called for. Let’s start with the disassembly of the slide into its component parts.

First, inspect the extractor. It doesn’t fit flat in the slide and should have a slight bow. This is normal and necessary for proper function. If the owner is having problems with the pistol ejecting properly it can often be traced to a bent extractor or a broken one. The hook should be sharp and not unduly worn. If the extractor appears to be the problem it can sometimes be bent slightly, but this is a job for someone who knows exactly what he or she is doing.

It might be best to return it to the nearest S&W Warranty Service Center. We’ll take the safety off the slide first. The early pistols (first generation) use a screw that must be turned out using an Allen wrench to remove the safety. This screw holds the lever on the left side of the pistol and, when removed, this small lever can be slid off.

The problem you might find with these kinds of safeties is that the screw becomes loose and the nature of the slide and safety geometry of the first generation guns might have allowed the slide to batter the safety and create a sloppy fit for the lever in its slot. The screw may have even broken off completely. S&W solved this problem by replacing the screw with a plunger arrangement to hold the lever in place.

Also, a slight modification to the safety body consisting of a small slot locking into the slide so the safety cannot move side to side when placed in the off position was made. To remove the lever on the right side of the gun’s safety, use an appropriate sized punch and push in the plunger. Cover the plunger with your thumb when removing the lever so the plunger does not fly out.

To remove the safety from the slide push down on the firing pin block on the inside of the slide and push in the firing pin with another small punch at the same time. Release the block and it will hold the firing pin in enough to allow the safety to start to come out when moved about half on, half off. When the safety starts to come out, use the punch to push the firing pin in enough to allow it to clear and you can push and pull the safety free of the slide.

When the safety is out, push down on the firing pin block and the firing pin will pop out. Be careful it doesn’t pop out to the other end of your shop. Note, there is a small plunger in the safety body itself. Next, punch the extractor pin down and out from the top of the slide. There is a small spring behind the extractor that will come out when the extractor body is removed. Use a short no-flex punch on this pin as it can be pretty tight. The rear sight must be driven out of its dovetail from left to right.

I carefully put the slide in a vise using leather padding to keep it steady while I used a brass drift to tap it out. With the sight removed, two small springs are revealed: The ejector depressor plunger spring and the firing pin safety lever spring. They are not the same. Note how

45 ACP and a Model 66 S&W .357 magnum. The 66 was THE cop gun back in the day. and where each must be returned. Removing these small springs allows the aforementioned plungers to be removed through the top of the slide. This ends the slide disassembly.

On the first two generation guns the grips are held to the frame by screws much like the model the grip pin out of the bottom of the grip (I went from left to right using a 3/32" punch.) This allows the rear grip insert to be removed along with the mainspring and mainspring plunger. On the third generation types, the grip is a single piece that must be spread apart slightly and slid off the frame. There are two small lips inside the grips that hold them in place.

I think this is a pain in the you-know-what, but if you have three hands it can be accomplished without breaking the grips. Also, the mainspring plunger fits into the bottom of the grip so the grip has to be pulled down at first to clear it. While difficult to work with, these kinds of grips do offer a thinner profile to accommodate the double stack magazine. On the left side of the gun the sideplate assembly is gently lifted part way with a small screwdriver. The sideplate holds two pins.

One is stationary to the plate and holds in most of the parts in the top of the frame. The other is the sear pin which can be easily removed from the plate and obviously holds the Notice the pronounced bow. sear. The sideplate is pulled up and out as a unit and this leaves most of the other parts ready to come out by simply pulling up on them or letting them fall out.

The parts that you can now remove are the sear, firing pin safety lever, sear release lever, ejector and magazine depressor, hammer and stirrup as an assembly, and maybe the disconnector (you may have to loosen the trigger pin to remove this.) A small tip when doing this job. Take careful note where these parts

came from and study the schematic. I try and keep all the assemblies, plungers and springs that go together separate and easily identifiable. If you take these guns apart frequently you will get a better feel of what goes where and the subtle differences that may be apparent in the different generations. For the first-timer or unfamiliar user I recommend taking digital pictures before complete disassembly and using a holder to hold all these tiny parts. An empty egg crate works as well.

Drive out the trigger pin using either a 3/32" or a 1/8" punch. The 1/8" punch may be a little tight and this pin comes out pretty easily. This will release the drawbar, the trigger assembly and the pins, and the plunger and springs that go with it. They really shouldn’t fly all to pieces and you may need to wiggle the drawbar a little to take it out the back of the frame. Cover it with your finger just in case it comes out with force.

The drawbar has a small copper plate secured by a rivet on the front that is called the trigger play spring. Take care not to bend the lips on this. The trigger is removed straight up through the top of the frame with some wiggling. The only parts left on the frame are the magazine catch and the sear spring. The sear spring is held in place by a very small pin running across the back of the frame. You will probably never have to remove these parts and I left the sear spring in place.

The magazine catch has a small plunger holding a nut in place to retain it. Just depress this plunger with a 1/16" punch and unscrew the nut, Notice the small plunger on the left side. This just lifts out. which will usually turn with finger pressure. The plunger, spring and catch can then be removed. There are two small springs on top of the frame at the rear called the ejector springs. They do not usually need to be removed but will pull out easily if you want to. This is as far as this gun can be disassembled.

Look for any damaged parts or anything that needs to be replaced. If all is well, clean everything. How you go about this is up to you. Some use a parts cleaner and a spray lubricant after everything dries. The gun I am working on was not all that dirty. I estimate only about 3,000 rounds have been put through it. I made do with a toothbrush, a little solvent and a degreaser. After it all dried, I used some Break Free to

lube and protect, letting that dry for awhile as well before starting to reassemble the gun. Starting with the slide, put the small extractor spring in place and the extractor in position. Start the extractor pin from the bottom of the slide. With the barrel in the slide, try a dummy case by locking the case under the extractor and almost, but not quite, pushing the barrel all the way into the locking position.

When the barrel is pushed back to the front, the case should remain held by the extractor and can be pushed downward and out by slight finger pressure. Next, insert the ejector depressor plunger and the firing pin safety lever plunger and their accompanying springs in the dovetail for the rear sight. The springs area different size from each other so make sure you put them in the appropriate place. Start the sight in the dovetail making sure the springs go underneath without kinking.

Tap the sight in until it is approximately centered in the dovetail. Inspect the firing pin, looking for a nice smooth hemispherical tip. As long as it wasn’t causing any problems before, just make sure it’s clean and lubed slightly. If it has been piercing or damaging primers it may need to be polished. Do not overdo it and make the tip round or flat. Hemispherical is the way it’s supposed to be. Also, it should not have any tiny lips or burrs on the side at the end.

A little emery paper or very fine grit abrasive paper should take care of that. Put the firing pin with its spring in place and push down on the ejector depressor plunger while pushing the firing pin in and release the plunger. This will hold the firing pin in place enough to start the safety part of the way in the slide. Remember that the safety can only go in so far unless the firing pin is slightly depressed more. The small plunger

The older generation has an insert instead of one-piece grips. on the safety has to be depressed before the safety will go all the way in its recess. If you are reassembling a first generation gun, degrease the screw and seat that holds the safety lever in place and apply some blue Loctite. If it’s a second or third generation replace safety lever plunger and spring and slide the lever over the plunger.

If you are working on a gun with a removable barrel bushing, insert the barrel and replace the bushing, then put the recoil spring and guide back in its small notch at the back of the barrel. I didn’t take the magazine catch out of my gun. If you did, put it back now, making sure that the large notch on the nut is down and the slot to use a screwdriver on it is up. Replace the catch and the plunger. Push the plunger in with a 1/16" punch and start the nut turning until it snaps in place.

The sear spring (which I also refrained from removing) would go in next—pretty simple. Just remember that one end of the pin is flattened and goes in last. Make sure the pin goes on top of the spring, not underneath. Guide the pin into the hole on the other side of the frame (it has a slight bow) and tap it slightly with the 1/16" punch to make sure it is secure. Remember how they go back in. The trigger goes in the top of the frame and the trigger spring and plunger are put in place.

As I said, the drawbar has a small plate on it held by a rivet. Sometimes this plate, called the trigger play spring, has the ears broken off and it will greatly affect the trigger pull. Fortunately, it is available as a replacement part and not difficult to repair. Make sure the drawbar is replaced correctly with this plate on the top side. Guide the trigger spring plunger in the hole in the end of the drawbar and the trigger

Don’t bend these little lips. itself into position. Hold it all together with one hand and insert the trigger pin to secure the complete assembly. The disconnector should be able to be replaced now. If you can’t get it to go in place you may have to remove the trigger pin to give clearance from the disconnector, but it’s much easier to leave that in place unless you have to. When the disconnector has been replaced the sear should be put in with the slot in the top, holding the disconnector so it can’t fall out.

The sear pin is removed from the side- The hammer was my grandfather’s. It has a polished head. plate and pushed in to hold the sear in place. Replace the hammer and its stirrup assembly. Start the first lever, the ejector and magazine depressor, then guide the sideplate pin through to hold them. Continue with the sear release lever and firing pin safety lever until the sideplate pin holds them. The sear pin can usually be started through the side plate with a light tap on the other side.

Replace the mainspring and plunger end and then slide the insert or whole grips onto the frame depending on the model being worked on. Replace the grip pin and put the frame and slide together and check for function. I like these guns, especially the third generation. They are reliable and durable and I keep one at my bedside. Usually you won’t find too much wrong with them except maybe broken parts or parts that just wear out from hard use.

Keep them clean and lubricated and you can shoot a lot of rounds before that happens. AG

Typical Smith & Wesson Semiautomatic Centerfire Pistol (Speci ications subject to change without notice) © @1988 by Smith and Wesson All Rights Reserved Used by Permission 1 Ambidextrous Manual Safety 2 Ambi. Manual Safety Lever 3 Ambi. Man. Saf. Lev. Detent Spring 4 Ambi. Man. Saf. Lev. Plunger 5 Ambi. Man. Saf. Lev.

Plunger Spring 6 Barrel 7 Barrel Bushing 8 Disconnector 9 Drawbar 10 Drawbar Plunger 11 Drawbar Plunger Spring 12 Ejector Depressor Plunger 13 Ejector Depressor Plunger Spring 14 Ejector & Magazine Depressor 15 Ejector Spring 16 Extractor 17 Extractor Pin 18 Extractor Spring 19 Firing Pin 20 Firing Pin Safety Lever 21 Firing Pin Safety Lever Plunger 22 Firing Pin Safety Lever Spring 23 Firing Pin Saf. Lev. Spg.

Ret. 24 Firing Pin Spring 25 Frame 26 Front Sight 27 Grip 28 Grip Pin Hammer Assembly 29 Hammer Hammer Pin (Sideplate Assembly) Magazine Assembly 30 Magazine Buttplate 31 Mag.

Buttplate Catch Assembly 34 Magazine Catch (Right Hand) 35 Magazine Catch Nut 36 Magazine Catch Plunger 37 Magazine Catch Spring 38 Magazine Follower 39 Magazine Spring 40 Magazine Tube 41 Mainspring 42 Mainspring Plunger 43 Rear Sight (Fixed) Rear Sight Assembly (Adj.) 44 Rear Sight Base 45 Rear Sight Base Screw 46 Rear Sight Body 47 Rear Sight Body Plunger 48 Rear Sight Body Plunger Spring 49 Rear Sight Elevation Plunger 50 Rear Sight Elevation Screw 51 Rear Sight Elevation Spring 52 Rear Sight Plunger 53 Rear Sight Plunger Spring 54 Rear Sight Slide 55 Rear Sight Windage Nut 56 Rear Sight Windage Screw 57 Recoil Spring 58 Recoil Spring Guide Assembly Recoil Spring Guide Recoil Spring Guide Bushing Recoil Spring Guide Plunger Recoil Spring Guide Plunger Spring 59 Sear 60 Sear Pin 61 Sear Release Lever 62 Sear Spring 63 Sear Spring Retainer Pin 64 Sideplate Assembly Sideplate Slide Assembly (Fixed Sight) 65 Slide (Fixed) Slide Assembly (Adjustable Sight) 66 Slide (Adjustable Sight) Slide Stop Assembly 67 Slide Stop 68 Slide Stop Pin 69 Slide Stop Plunger 70 Slide Stop Plunger Spring 71 Stirrup 72 Stirrup Pin Trigger Assembly 73 Trigger 74 Trigger Pin 75 Trigger Play Spring 76 Trigger Play Spring Rivet 77 Trigger Plunger 78 Trigger Plunger Pin 79 Trigger Plunger Spring