Mod 41

[dek]

I've an old A series 41 that's started giving me a weird problem. I'm shooting CCI SV and loading the mag to capacity. The first nine rounds fire without a problem but the tenth round the firing pin does not indent the rim and doesn't fire. I extract the round and there is no indent. I reload it and it fires. Load a different mag to capacity, same thing.
What could be causing the firing pin to not go fully forward on the tenth round? I didn't have time to play around with other ammo types or mags. When I can get to the range next I'll try some variations and go from there. Your thoughts? Thanks, Dennis

 

[john traveler]

The only thing that I could think of that causes your 10th round failure-to-fire is that the slide doesn't fully return to battery and doesn't fully disengage the trigger disconnector that prevents hammer fall.

Try cycling the slide with empty magazine and a FIRED case in the chamber. Does it produce firing pin dents?

I would start the diagnosis with a detailed disassembly and solvent cleaning of the trigger linkage/disconnector, slide hold-open, and associated linkages.

 

[dek]

John, thanks for the reply. I should have mentioned, in my first post, that the hammer does fall on the tenth round but fails to push the firing pin enough to indent the rim. I have to eject and reload that round and it subsequently fires. After reading your suggestions, I'll give it a thorough cleaning and try it again. Dennis

 

[chief38]

Have you tried using a different magazine?

 

[dek]

Have you tried using a different magazine?

Yes, I did try two other mags - same symptoms. I also started having ignition problems on other than last round in mag.
On those rounds that fired, firing pin indent was solid. When they didn't fire, there was no evdence that the firing pin struck the rim. When reloaded, it fired with good indent.

I thoroughly cleaned and checked each part in the slide. Dirt was minimal to nonexistent. The firing pin may have been slightly peaned from dry firing, at one time, and thereby shortened. However it doesn't evidence such damage. The firing pin, spring and channel have been thoroughly cleaned and dried. All other parts cleaned and lubed. Back to the range tomorrow for a test.

Thanks for all the replies and suggestions.

 

[TOM BECKWITH]

Check to see if mag is dragging on follower, slowing down the slide on last shot??

 

[Joni_Lynn]

I'm thinking Tom may have hit the problem. If it's the last round then it may be the mag.
Regardless of how many rounds are loaded in the mag it still does it on last round right?

 

[dek]

At first it was basically the last round. However, during further testing it began to happen anywhere in the string but usually only one in five. I went to the range today and it still exhibited the same problem. I'll pull it apart and check the disconnect/magazine and see if that might be the culprit. When it doesn't fire there is no mark on the rim so it just might be the disconnect failing to allow the bolt to go into complete battery. Maybe also time for a new recoil spring. The current spring is original to the gun. I think it's time. Thanks again for the replies and suggestions. Back to work.

 

[dek]

still stymied

I completely cleaned the barrel, lower receiver, disconnector, etc. I replaced the firing pin and spring and the recoil spring (there was a difference of an inch between the old and new recoil spring so that, I'm sure, was part of the problem). So, off I go to the range with four different magazines (3 old style and 1 new w/plastic follower). I load each magazine with with 5 rounds each, load and fire. 1st mag all five fire. 2nd through 4th mags the last round fails to fire although the slide is all the way forward, the hammer falls but there is no indent on the case and consequently no fire. I reload all four mags with 10 rounds each. On all four mags, I have the same failure to indent on the last round.

 

[TOM BECKWITH]

DEK, sounds like you have done about everything right. See if VIDO at S&W is still working - he is the S&W 41 guru.

A thought, see if an empty mag locks up tight with the slide open. The mag lock can be tightened by depressing the mag catch plunger and turning the mag release button - but play slowly to see if it changes the lockup.