Misfire in DA

[guesser]

Model 36 no dash. Had it out for exercise the other day, running it DA I had 4 rounds out of 50 that failed to fire. They all fired when retried in SA. Is this a malfunction of hammer spring or rebound system or what. The gun has seen very little use; S/N is J2899XX.
Thanks to any and all.
I used the search function but my google foo is weak and I found nothing about this in "J" frames.

 

[Wiregrassguy]

Could be a number of things. First I would clean the action to make sure there's not any debris interfering with the double action Sear. If you feel comfortable doing it open it up and spray the inside with Auto Parts, carb or brake aerosol cleaner. Then lightly Lube it, and see if that fixes it. Also you might try a different manufacturers ammo, unless you're handloading. Could be the primers are a little hard for that gun. Lastly I would replace the mainspring. Wolff Springs will sell you a pack of three I believe come in different strengths.

Guy

 

[Pisgah]

I can think of two likely reasons. First, if the ammo was reloaded (or, in fact, factory loaded -- but that's rare) the primers might not have been quite fully seated. In that case, often a first strike will seat them all the way and a second will fire them. Second, the mainspring may have been shortened to improve the trigger pull. This works, but is risky with a J-frame, as I have seen even a mere 1/2 a coil too much removed being the difference between reliable firing and sporadic misfires.

 

[deyomatic]

I had a similar problem with two different Colt Official Police revolvers.

Is it the same chamber each time? What does the dimple from the hammer look like on the primer when it didn't fire?

In MY first case, a new mainspring fixed the problem. In my second case, I sent it to a Colt guru, it was still messed up, and am going to send it back so he can fit a new cylinder- it was getting cylinder throw by on one chamber- and only that one. I marked it with a small piece of masking tape and it would only fire in SA on that one chamber.

 

[guesser]

If it was a Colt I'd not have to ask, as I've pretty well got them figured out. But S&W is not really my game for the lock work and "J" is different than "K". I have to ask for help.