Friday, November 9, 2018

Firing Pin Stop

The firing pin stop in the back of your 1911 holds the firing pin in.  Obviously.

It does other things, too tho.

When the slide cycles back, the lower edge of the firing pin stop comes in contact with the hammer.  It has to push the hammer back to continue this recoiling operation.  The hammer is held forward with the mainspring, so the recoiling slide has to overcome this spring tension.

The shape of the firing pin stop that contacts the hammer can determine how easy or hard it is for the slide to work.  The contact point from pin to hammer acts like a fulcrum.  A squared off firing pin stop lower the fulcrum making it harder to slide and come out of initial lockup, a rounded firing pin stop raises the initial fulcrum point making it relatively easier to push the hammer out of the way.  It's also more gradual. 

How hard or soft the recoiling slide has it impacts how much recoil is 'felt'.

The lower the fulcrum, the harder the initial big bump in recoil, and the more you 'feel' the recoil.  So why do people use a squared off firing pin stop?  There gun isn't tuned up and they are trying to achieve something else.  Something that might be solved with better fitment, or different spring weights, or a different balance with opposing springs.  I'd change the recoil spring and firing spring first before trying to resolve my problem with a firing pin stop.  In fact, the angle on my current firing pin stop isn't rounded enough,  I might mess with that some.  Make it more angled/rounded.

But man, folks have strongly held opinions about this little part.

It is a relatively easy part to fit and replace, so if it all goes to poop for me, I can try a bunch of different geometries.  The gunsmith says round that puppy for less felt recoil.

Even more important, being sure there is no slop in your firing pin stop, especially how it holds your extractor in place.  You want as little wiggle as possible there.  

1 comment:

Will said...

What I can't remember is whether the recoil spring rating was changed when they modified the stop plate. That large radius effectively changes (lowers) the total recoil spring power that controls the slide retardation. My memory is that the recoil dynamics is noticeably different between the two, but I'm usually working with Officers Models, so not exactly oranges to oranges when looking at the Govt Model. Plus, it's been years since I have shot them, and my memory is not so good anymore. Others have commented that the recoil doesn't seem to have a noticeable twist with the original plate, compared to the more common -A1 version. That's what I also recall, but the details are fuzzy. The Officers runs springs rated from 22-24 lbs, and the slide is a blur when moving. The Govt Mod seems to just trundle along in comparison (except the 10mm).