S&W 15-2 firing pin problem

[4D5]

I am having problems with my 15-2 firing pin. I have occasional light primer strikes and subsequently failure to fire.

I did some checking and found that the nose of the firing pin is striking the top of the frame in the hammer slot. I think this is where I’m getting the occasional light primer strike.

I checked the firing pin and it floats freely in the slot in the hammer, however the firing pin is not retained in the down position by a spring (or it appears so)

My question is… you guys with 15-2 revolvers, is the firing pin on your 15-2 retained in the down position by spring pressure?

I called S&W earlier and the rep said that not all firing pins have springs.

This is a link to my post on my 15-2 in question.

http://www.thehighroad.org/showthread.php?t=493061

I’d appreciate any feedback from 15-2 owners.

Thanks, 4D5

 

[Old Fuff]

I can't say if your model 15-2 has a spring-tensioned hammer nose or not; but if it doesn't one can easily and inexpensivly be installed.

Before you get too involved with the hammer nose (firing pin), check the head space, and cylinder end-shake. Also look for marks on the side of the hammer or hammer nose that suggest that the hammer is off-center.

 

[Stophel]

Pin bent, perhaps?

 

[Oro]

As a double check on the diagnosis, have you checked your mainspring screw and/or mainspring itself? Even w/o a pin spring, the f/p ("hammer nose") should not be able to pivot far enough to strike the top of the channel during the hammer strike unless it is bent as Stophel said, or the channel was machined incorrectly. Perhaps the channel is indeed low, but double check the spring as it's usually the most common source of this problem and worth ruling out independently.

Check the screw on the front strap of the grip. Make sure it's tight. If 1/2 turn or more loose, tighten it. If not loose, back it out and inspect the tip - should be pointed, not filed flat (actually, check the tip either way just to be sure it has not been fiddled with). If the screw checks out, re-install it and then remove a grip panel. Look and see if the mainspring itself is flat, or if it has a "rib" in the center. Aftermarket mainsprings can also cause intermittent light strikes and are identifiable by their rib.

 

[madcratebuilder]

No spring tension on the firing pin of my 15-2 or 15-3. If I had an occasional light primer strike I would look at the hammer spring and tension screw. Is the tension screw backed out?

 

[4D5]

I checked the strain screw and it was/is screwed all the way down.

All hammer/frame/firing pin dimensions look ok visually with no obvious abnormal wear etc.

I'm suspecting something else is going on because for the fired cases there is a very substantial firing pin dent, so that would indicate that there's something intermittent going on. Otherwise, all the cases would have light strikes. My current suspicion is that the hammer block may not be dropping completely and causing partial interference.

 

[Black Knight]

It sounds to me that there may be some sort of gunk or debris in the action since it seems to be intermittent. You may need to remove the sideplate and give it a thorough cleaning inside. If you don't feel comfortable removing the sideplate a competent gunsmith will be glad to do the job for you. That might be a good idea anyway as he/she can give it a good check up to see if there are any seriously worn parts.

 

[Oro]

I checked the strain screw and it was/is screwed all the way down.

Did you also remove it to inspect the tip and also inspect the spring shape itself?

so that would indicate that there's something intermittent going on. Otherwise, all the cases would have light strikes.

Strain screw/mainspring issues and mainspring issues can indeed be intermittent as both I and madecratebuilder have mentioned and experienced.

My current suspicion is that the hammer block may not be dropping completely and causing partial interference.

While theoretically possible, it is extremely unlikely. The first diagnostic step in this case is to check that screw tension, screw tip, and then the spring itself. The tip of the screw should be blued and tapered and not show any bare steel or evidence of filing/flattening of the tip.

 

[madcratebuilder]

Is it possible a previous owner installed a spring kit or filed the end of the tension screw? Does the hammer show signs of it dragging on the frame? A good clean and lube, maybe shim the hammer if it's rubbing.

 

[4D5]

It's the strain screw

First of all, thanks everyone for your input.

I finally had a chance to check closer. Well sure enough a kitchen gun plumber shortened the strain screw, it has a flat shiny tip

The main spring appears to be dorked with too :banghead: It’s shiny all over and has been thinned on the sides. It doesn’t look anything like a factory original.

I checked the barrel/cylinder gap and it’s right at .006 and the brass to recoil shield is right at .008.

I’ll be calling S&W tomorrow to order replacement parts.

Thanks again everyone for your assistance and input.

4D5

 

[Stophel]

The firing pin shouldn't be striking the frame no matter what may or may not be wrong with the mainspring.

 

[madcratebuilder]

I finally had a chance to check closer. Well sure enough a kitchen gun plumber shortened the strain screw, it has a flat shiny tip

The main spring appears to be dorked with too It’s shiny all over and has been thinned on the sides. It doesn’t look anything like a factory original.

Those are fairly common old school gunsmith mods. Back before all the aftermarket parts makers if you wanted to hot rod your S&W you had to work with oem parts. You may only need to replace the strain screw.