Author Topic: 75 firing pin issue  (Read 258 times)

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Offline timmy75

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75 firing pin issue
« on: January 24, 2020, 08:29:56 AM »
Gun is 1995 CZ 75 "transitional".

i have tried to make it work with softer FPS, it only works with some super hard type of stock FPS. i can not realize why?

whey I use even a bit softer spring it always get stuck in forward position.

i have tried with 2 types of softer FPS and stock shadow2 spring. it gets stuck. it only works with stock firing pin it came with.

i was thinking maybe a gun is a problem, than i put that stock 75 firing pin in shadow 2. again, it gets stuck in S2 with any FPS other than stock 75 FPS it came with.

extended FP and Shadow 2 stock FP work booth in any gun with any avaliable springs.


EDIT:
(pictures)


« Last Edit: January 24, 2020, 08:57:09 AM by timmy75 »

Offline Oldbear

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Re: 75 firing pin issue
« Reply #1 on: January 24, 2020, 08:49:25 AM »
I’m not sure I understand, but it sounds tome like your original pin may be out of spec seeing as how it doesn’t work in the S2.   If the S2 pin works in both, I’d suggest trying a new “srock” pin in the 75.

Offline jurek

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Re: 75 firing pin issue
« Reply #2 on: January 24, 2020, 09:27:30 AM »
I'm also not sure if I got everything correctly...however:
- 1995 is called "transitional model" and hard to tell which replacement parts fit better - before 1995 or after 1995 models?
- if firing pin gets stuck in forward position, softer spring won't help
- "extended" and "S2" firing pins from your pictures are different than "75 stock" one
- have you cleaned firing pin channel in your firearm?

Offline M1A4ME

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Re: 75 firing pin issue
« Reply #3 on: January 24, 2020, 10:17:34 AM »
Your second picture makes me think the straight section of the firing pin - where the firing pin return spring sits, is long enough that it jams up in the end of the firing pin channel when it reaches full forward movement - either in the channel or by binding the lighter springs between it and the channel.

Often, a lighter spring is a smaller diameter wire.  It may be that the smaller diameter allows it to bind up between the firing pin and the firing pin channel in one of two ways - the firing pin goes farther into the channel (that straight section) or the spring itself can be forced further into the channel due to it's smaller wire diameter and less "strength" of the spring.

My only suggestion would be to replace the firing pin with a newer firing pin (looks like a Pre B firing pin - so don't order a firing pin for the B model CZ75s) if you want to try a lighter return spring or stick with what you have.
I stopped carrying the SIG 556R.  SIG changed models and couple/three times and stopped supporting it with parts.  So, I stopped supporting SIG.  Back to the tried/true AR15 Carbine.

Offline timmy75

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Re: 75 firing pin issue
« Reply #4 on: January 24, 2020, 12:47:57 PM »
M1A4ME i think you are right. stock 75 is much bigger in coil diameter than other 3 springs.

i will buy the same extended FP and the same softer FPS like I use in my Shadow2. it works.

unfortunately, when I use my stock 75 FP and stock 75 FPS with #9 and #10 main spring it lounches pencil 2-3 inches only

Offline M1A4ME

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Re: 75 firing pin issue
« Reply #5 on: January 25, 2020, 05:57:23 AM »
My Glock and M&P (the 1.0 models) won't even lift a pencil completely out of the barrel.  The XDMs will make it jump completely out of the barrel. 

The pencil test is good to make sure the firing pin is actually coming through the breech face, as it has to in order to ignite the primer, but apparently (based on the Glock/M&P) results, even a lighter firing pin striker on the primer can still do the job.

I stuck a pencil in the ceiling at work one time, with a 1911.  Had to get up out of the chair, reach up and pull the darn thing out of the celotex panel.  Never seen anything launch a pencil like a 1911, but the still go bang.

When you get the parts and install them, please be sure to come back and post on the thread to let everyone know how it worked out for you.
I stopped carrying the SIG 556R.  SIG changed models and couple/three times and stopped supporting it with parts.  So, I stopped supporting SIG.  Back to the tried/true AR15 Carbine.