39-2 Full Automatic

[cdiggs]

The model 39 has been my favorite semi auto for many years. My present 39-2 just went full auto on me. I did not like it. This was the scenario: I inserted a full mag with the slide held back by the slide lock. Normal so far. I released the slide by thumbing the slide lock down, finger off the trigger, which is my normal practice. The pistol fired at least three rounds instantly (yes, I'm sure). I was too shook up to count the rounds left in the magazine, but they fired normally. The ammo was commercially reloaded 115gr FMJ rounds that I've fired a couple of thousand rounds of with no problems. ***?

 

[murphydog]

I gather you and no one else were injured? That is most important.

Closely following this is that you now have a full-auto firearm, inadvertent or not. Do not try to fire it again, and I would immediately contact S & W Customer Service and have them advise you what to do with the gun. They may no longer have parts for the 39-2 but they can tell you your best course of action.

 

[okie john]

Sounds like a slam fire. Unload it, then drop the slide on an empty chamber. If the hammer follows, send it back to Smith as advised above.

If the hammer doesn't follow, then detail strip and clean the slide, especially the firing pin and channel, and look for broken/worn parts and especially unburned grains of powder. If everything looks OK, try it with ONE round. If it fires when you drop the slide, send it back to Smith. If not, you should be good to go.


Okie John

 

[cdiggs]

Thanks guys. The muzzle was pointed in a safe direction. No injuries. After the automatic burst the hammer was back and the slide was locked up normally. I fired the rest of the magazine in semi-auto. It functioned perfectly. I'm just itching to disassemble it myself to see if the sear/disconnector/hammer spur is chipped or what. I have fully stripped 39's and have a good book for what I don't remember. I think, though, that I agree I should have S&W blessing before I holster it again. Shame. It's my favorite carry piece.

 

[CALREB]

The sear spring may be partially broken or the pin holding it in.Weak sear spring can cause this.

 

[cdiggs]

Thanks, I plan to get the thing stripped this weekend and talk to the S&W folks Monday. Maybe they've seen it before. I didn't mention it before, but I had fired probably 8 full magazines through it before the Auto bit, and I finished the Auto magazine with no troubles. Sounds interesting. Dangerous, but interesting.

Thanks Again, I'll post when I know something else.
JJ

 

[cdiggs]

OK, I stripped the pistol and here's what I see. The firing pin, the trigger, trigger linkage, sear, and disconnector are all good. No chips, no cracks, no funny wear angles, no hits, no runs, no errors...the attached pic shows the only boo-boo I can find. One of the two hammer notches is chipped. The top notch in the forefront shows a tiny piece missing. This is the first notch, not the single action or double action notch. I'm sure this is a problem, but I don't see how this could go full Auto.
Any explanations?

Thanks
JJ

 

[500 Magnum Nut]

You can test that the disconnect is working like it should. This test is the same for any semi-auto.

Empty gun, magazine removed.
Cock pistol by running the slide
Dryfire pistol, maintain pressure on the trigger
Cock pistol again by running the slide
Now let go of the trigger, you should hear a click

(If no click, the disconnect is not working = FULL AUTO)

Dryfire pistol again

I'd replace the sear spring and mainspring if the condition occurs again or if the gun fails the dryfire test.

 

[RGPM1A]

I would also check to make sure the firing pin is not stuck or sticking in the forward position -that would cause full auto fire . If the gun has seen a lot of use or cleaning good chance the firing pin tunnel is gunked up. The chipped hook it one of the half cock notches. I would replace the hammer.

 

[scooter123]

I would also check to make sure the firing pin is not stuck or sticking in the forward position -that would cause full auto fire . If the gun has seen a lot of use or cleaning good chance the firing pin tunnel is gunked up. The chipped hook it one of the half cock notches. I would replace the hammer.

I know nothing about working on a model 39 but this is the most reasonable explanation I've seen for this happening. If my memory hasn't browned out on me, some of the early machine guns used a locked firing pin. In addition, a stuck firing pin would also explain the slam fire you experienced.

I'd also try that disconnector test mentioned previously but since the problem seems to have cleared itself up it's likely your gun will pass this test.

Personally, I'd be a bit more freaked out by something like this than you seem to be. If that had happened to me that gun would have been unloaded immediately and locked in my case. The simple fact is that the ATF takes a rather extreme view of the general public having a machine pistol in their possesion without the proper license and that fellow in SC serving a Felony sentence for a similar incident comes immediately to mind.

I also think a call to S&W is very much in order. I don't know if they still have the parts to service the model 39 but if they do, IMO a full factory tuneup is the wisest course of action.

 

[tomcatt51]

The chipped "hammer notch" is obvious but the other "notch" on the same side looks damaged also. I would be surprised if the sear wasn't damaged/worn also.

 

[bs369]

Full auto..

Call S&W ASAP. I had the same thing happen on my 1911 gunsite model...As soon as I called they email me an overnight shipping tag to get it to them right away...Needless to say it was fixed and returned in less than 10 days..

 

[cdiggs]

Wow, I wasn't expecting this much of a response. This is a VERY serious matter to me, and I appreciated all of y'alls time. This afternoon I reassembled the pistol, removed the extractor, and put a snap cap in the chamber. I loaded an empty mag cycled the slide, the slide caught on the slide lock. I thumbed the slide lock off, just like I did before the 'event'. The hammer stayed back, and I dry fired the pistol normally. I did this 100 times (really). Everything worked perfectly 100 times. I'll talk to S&W tomorrow. I'll post results.
As far as the responses go, thanks, and:
500 Mag
Disconnector is OK
RGPM1A:
Firing pin is OK, tunnel was clean, now it's really clean, pin has no burs, scratches, dents. Spring seems in good shape.
Scooter:
I was/am very upset by this. I had to empty the magazine to see if it would happen again. We were in the sticks, safe berm for backstop, after I emptied the pistol I put a trigger lock on it and put it in it's case, inside a larger gun case I use to transport multiple pistols. I sent S&W an email last night and will call tomorrow. You have misread just how freaked out I am. But I have seem many, many items with intermittent problems and they are the hardest to figure out. Had I been at the public range, I would have, after the auto burst, disassembled the pistol and packed it away. My email to S&W included a request for an estimate for a 'rebuild'. If I can't afford to fix it now, it will be disassembled and put away until I can.
Tomcat:
I can't say if any other notches aren't damaged, but they look the same from one side of the hammer/sear to the other. The mating surfaces are shiny and smooth. It will take S&W to tell if they are out of spec.
bs369
Sent the email, I'll call tomorrow. Repair depends on money, money changes everything. As old as the pistol is, I can't imagine it being warrantied in any manner, regardless of the problems.
Stay tuned.

Thanks again
JJ

 

[cdiggs]

S&W

I did talk to S&W Monday, and they're sending me a package to send the pistol back in for repairs. Haven't seen it yet.

 

[Sebring Pop]

The exact same thing happen to my Model 41 (1979 vintage) about 5 years ago. Living in Connecticut made it easy, I drove up to Smith in Mass, presented my problem and had it fixed like new in about a week. They told me they had to charge me for parts but not for labor because it is a competition gun.

Best of luck to you.

Thanks Pop

 

[cdiggs]

OK, just heard back from S&W. I guess they stay pretty busy, it's been a couple of months since I sent it in. I sent a letter explaining exactly what happened and, without naming any details, S&W said they'd fix it for $74.00. WooHoo! Didn't ask how long it would take. Don't care.

Thanks
jj

 

[triggerman770]

39-2 Full auto

and going forward you might try "slingshotting the slide" instead of dropping the slide via the "slide stop" lever. May or may not make a difference, but won't hurt.

 

[cdiggs]

Triggerman:
I'll try the 'slingshot' for a while, but my hands are such that I don't have to shift my (one handed) grip to hit any slide release I've ever used. That, and trying to change a forty year habit...

Thanks
JJ

 

[cdiggs]

Got it back! Looks great, feels great. They replaced the sear and sear release lever. Haven't had a chance to get to the range, but I've got a lot more confidence in this old pistol now. Still one of my all time favourites. As soon as I got it back I stripped it to see what was replaced and noticed, oddly enough, that the slide stop button was missing. This was staked in place, and I assume it was OEM, but anyway, I called and they are sending a new one.
Thanks for all the comments, I hope this is case closed.

JJ