Safety Question -- Please explain Safety operation and function on 39-2

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Please explain up down safety operation and function on 39-2

Operation and function when hammer is cocked

Operation and function when hammer is down

Which direction is safety on (up or down)

What happens when hammer cocked while safety down

What happens when hammer cocked and safety up

Does decocking hammer turn the safety on or off?
 
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Please explain up down safety operation and function on 39-2

Operation and function when hammer is cocked
  • Hammer can only be cocked manually with the safety disengaged. with hammer cocked, Single action first shot, auto load, subsequent shots single action
Operation and function when hammer is down

  • With safety disengaged, first shot is double action, subsequent shots single action


Which direction is safety on (up or down)
  • Engaged when down


What happens when hammer cocked while safety down
  • Hammer will not cock with the safety engaged (down)


What happens when hammer cocked and safety up
  • Pistol in in ready to fire mode, safety disengaged, all shots single action

Does decocking hammer turn the safety on or off?
  • Decocking lever and safety are one. Decocking the pistol using the decocker engages the safety. the decocker rests the hammer against the hammer block preventing the hammer from contacting the primer. Lowering the hammer without using the decocker leaves the hammer resting on the firing pin. Engaging the safety (down) moves the hammer back against the hammer block
 
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Prove it to yourself--SAFELY-- how it works!!

Bushmaster;

I too had personal reservations about the function of the de-cocker mechanism on my 39-2 and years later when I got a 639. It always seemed to me that when putting into de-cocker mode that hammer made an impact that was accompanied with sound like it would have fired had a live round been in the chamber.

Then I noticed the 1/16" (or less) difference of hammer down when firing vs hammer down on de-cock, so I asked this forum and received a great tip on how to prove it to yourself, safely using of course an unloaded firearm, and a #2 pencil.

If you know how to do it (I don't know how to bring up an old post of mine and post it here), please look for my post titled "new to me Model 639- UPDATE" which was posted on April 7, 2022 at 04:20 pm in this sub-forum (S&W semi-auto pistols).

Just make sure you use a UNsharpened #2 pencil.:D

I repeated this "test" with the pencil so many times with my 39-2 and the 639 that my wife said I was acting like a little kid at Christmas who got his first toy dart gun and was shooting the darts all around the house.

I can tell you that I am now a fan of this safety/de-cocker mechanism and would not hesitate to carry in this condition should I ever want to.

Watch for the trigger pull of the second shot after the first shot is DA from the de-cocker position....first shot = heavy pull; second shot almost non-existent...so watch out for it!
 
If you rack the slide with safety engaged, the hammer will fall (decock) as soon as the slide is closed.

The hammer block will prevent the hammer from hitting the firing pin.

NOTE that first gen S&W pistols 39/39-2/59 and Model 52 do not have firing pin lock safeties are thus are not “drop safe.”
 
Great Thread. Cleared up a lot of questions. True, its not as positive as the firing pin block pin that came later, but never had a problem with any of mine. Mike
 
Maybe I will fire my new to me nickel 39-2 in high condition and this will be important information.

Do not plan to carry it as I will not practice enough to be proficient
 
FWIW, DO NOT get in the habit of always de-cocking any gun using the safety/de-cocker, particularly on the Model 39/59 and follow-ons. While my department's armorer for several years I replaced several broken Model 39 safetys because of this. You can safely hold the hammer with your thumb, then apply the safety to block the hammer, then lower the hammer onto the safety instead of letting it drop and strike the safety.

We were the second major department, I believe, to adopt the Model 39, in 1970 as I recall, and had about 400 of them.
 
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Correct me if I’m wrong but the 39 series is “drop safe”, but only when the safety is engaged. Unlike a 1911 where the firing pin is free floating and held to the rear with the firing pin spring (just as the 39 is with the safety disengaged) when the safety is applied to a 39, as the barrel rotates to decock the hammer and as it moves to the safe position and shields the end of the firing pin from the hammer dropping, a portion of the barrel also engages a notch in the firing pin, locking it in place to the rear. You can test this function by pushing the rear of the pin with the safety on and off and seeing it depress with the safety disengaged and locked in place with the safety engaged.
 
Correct me if I’m wrong but the 39 series is “drop safe”, but only when the safety is engaged. Unlike a 1911 where the firing pin is free floating and held to the rear with the firing pin spring (just as the 39 is with the safety disengaged) when the safety is applied to a 39, as the barrel rotates to decock the hammer and as it moves to the safe position and shields the end of the firing pin from the hammer dropping, a portion of the barrel also engages a notch in the firing pin, locking it in place to the rear. You can test this function by pushing the rear of the pin with the safety on and off and seeing it depress with the safety disengaged and locked in place with the safety engaged.

Your correct, the firing pin is only locked with the slide safety engaged. A Friend was issued a model 39 and it was common to carry the 39 slipped inside the waist band at 3-4 O Clock with no holster.

My Friend was in a shower room and the 39 dislodged from his waist band with the safety in the fire position. The muzzle end of the pistol impacted the tile floor and the chambered round fired from inertia. Fortunately no one else was around and no one was injured. This incident occurred in the early 70’s when it was required for off duty Officers to carry their model 39. There was no issued concealment holster so it was common to tuck the 39 in the waist band.

One of the changes to the S&W 439 second generation series was the addition of the firing pin (drop safety) block.
 
Testing a decocker with a pencil is also recommended on the CZ 52 pistol. On a gun worn in a particular way the results can be disturbing. ;)
 
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