Sunday, November 28, 2010

Disabling a 1911 firing pin safety

Is it safe to do this? 

Yes, but only for a competition gun.  It would be foolish to disable any safety mechanism on any gun you might use for self-defense.  The DA and civil lawyers will have a field day with you.  Don't disable any safeties on a carry or house gun.  Ever. 

What's the problem?  

I've been having misfires on my S&W 1911 due to light primer strikes.  We tracked the problem down to the Schwartz firing pin safety.  This system consists of a plunger in the slide that blocks the firing pin unless it's levered out of the way by the grip safety.  The flaw here is that it's possible to activate the grip safety just enough to allow the trigger to release the hammer, but not completely move the plunger out of the firing pin's path, causing the pin to graze the plunger, losing enough momentum to cause a light primer strike. With my skinny hands, this happens a lot. 

How to fix it?  

Two steps.

1) First remove the plunger, spring and plate from the slide.  To do this, unscrew the rear sight and drift it out.  The three parts will come out of the top of the slide very easily.  It'll look like this:
Note the plunger is marred from contact with the firing pin. 

2) Modify the lever so that it doesn't get caught in the newly empty hole in your slide.  If you leave the lever as is, it's very possible for the tip to get caught in the hole (heh heh) during recoil, damaging the lever and hammer pin, and possibly other parts.

The stock lever looks like this when it's in its highest possible position.

Blacken the exposed part with marker, then do a detail strip to remove the lever from the frame.  Once it's removed, simply grind or cut off all the black part, plus a few 100ths more.  The idea is to make it so this part can never get in the way of the slide.  

Here's what it looks like in the frame after grinding and, of course, deburring.  

In it's highest position, the lever is just below flush with the frame. 

That's really all there is to it.  I want to really emphasize that if you're having problems with your S&W 1911 firing pin safety, the best thing is to call their great customer service department, and send it to them for adjustment.  Only disable the safety in this manner if it's strictly a competition gun, and you know what you're doing.  

No comments:

Post a Comment