The Original CZ Forum

GENERAL => CZ Gunsmithing => Topic started by: schmeky on May 13, 2013, 09:20:36 PM

Title: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on May 13, 2013, 09:20:36 PM
There is a design flaw in the CZ OEM firing pin used in CZ models with a firing pin block safety, i.e. SP-01, P-01, PCR, 75B, etc.  Good news is there's a solution.  I will show details and the "fix" in a few months. 

In the process of designing/creating a FP that should run practically indefinitely, and should allow for dry firing w/o issue.   
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: viking499 on May 13, 2013, 09:26:32 PM
Great.......now I have to spend more money......... ;)
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Riptide439 on May 13, 2013, 09:32:07 PM
Glad I have CGW FP in my 2.  :)
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: JonNC on May 14, 2013, 01:53:54 PM
Once again...

(http://i.imgur.com/ZsJHyuI.jpg)
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Stuart on May 14, 2013, 03:08:16 PM
Ought to be good.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: tekarra on May 14, 2013, 07:27:19 PM
Looking forward to seeing details of the flaw and the fix.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: BigHeat on May 14, 2013, 08:45:46 PM
waiting with money in hand.  my gun always needs a new upgrade
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on May 14, 2013, 10:43:51 PM
It's amazingly obvious.  I can see why the OEM spring pin breaks.  As soon as I have a working prototype, I'll post some pics.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: 1SOW on May 15, 2013, 12:09:20 AM
The interrupt  design also serves as the FP travel stop?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Cesar on May 15, 2013, 01:45:16 AM
The original design is still relevant; think of when (1975) and where (CZ) the design came from.
How many rounds were those guns expected to go thru in their lifetime? Or, without service?

How cheap and easy it is to replace the pins?

Dave is a great guy, I'm not arguing there at all, far from that, opposite actually.

The gun design back then had quite different roots and application, that's what I'm to say.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: 1SOW on May 15, 2013, 10:18:24 PM
Cesar is right.  I think what may have brought this issue to light is competition or serious range shooters dry firing a lot.  I suspect action round count went up quite a bit  since design inception.
On the other hand, my pins with 60K rds never broke, but I had put in a new one-piece  pin to make removal for cleaning easier.  The original design was very durable for normal use.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: HankC1 on May 19, 2013, 08:28:50 PM
I had a 75B broke a firing pin when I got it used. The first owner appears dryfired it a lot. CZ sent me a firing pin for free. The double roll pin is not that friendly when a firing pin needs to be replaced or removed for cleaning. One reason I switched to Tangfolio!
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on July 19, 2013, 04:30:42 PM
I wanted to show one of the flaws in the CZ firing pin.  Look where the .125" retaining pin rests against the retaining shoulder of the FP.  You can see there is a mis-match.  The area where the FP actually contacts the retaining pin is a very small area.  This is where the FP peens and eventually can develop a crack.  This also beats up the stock roll pin retaining pin quickly if dry-fired a lot.
(http://i1082.photobucket.com/albums/j367/schmeky1/NewWebsitePics001_zps2798abe5.jpg)

Here is how it should look with the FP shoulder mating perfectly with the retaining pin.  This would distribute the inertia forces over a much wider area.  Combined with the ideal FP material, in this case S-7 tool steel, and the proper heat treating, peening should be virtually eliminated, even with prolonged dry firing. 
(http://i1082.photobucket.com/albums/j367/schmeky1/NewWebsitePics014_zpsa11d95a2.jpg)
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: BigHeat on July 19, 2013, 08:50:48 PM
nice catch in the gap between the retaining pin and the FP.     So what's the second flaw?   Also when do you think these "new"  FP with be ready for sale?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on July 19, 2013, 09:23:15 PM
This where a CZ FP breaks.  This taper narrows down sharply, too sharply.  A more gradual and thicker taper will make the FP much stronger.  Lastly, I had a CZ FP analyzed and it is made from an average grade of tool steel.  S-7 tool steel is vastly superior but expensive.  CGW CZ FP's are currently made from S-7.

(http://i1082.photobucket.com/albums/j367/schmeky1/NewWebsitePics005_zps6a22f565.jpg)
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: skipper on July 20, 2013, 02:56:49 PM
Schmeky is a genius with the CZ, who would have thought. When reading about fp issues I get tempted to remove the fpb. It would be great to have a safe fix for removing the fpb such has evolved for the 1911 using a titanium fp to match the fp pin to eliminate the flawed design.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Xenogy on July 20, 2013, 04:39:26 PM
Do the current CGW firing pins have this "fix" already? Thanks

Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: CAGLS on August 23, 2013, 12:33:31 AM
When will these be available?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on August 23, 2013, 11:08:23 AM
Xenogy,

The current CGW FP's are almost like the revised versions.  We relieve the area on our firing pins where peening can occur.  Our FP's are already made from S-7 tool steel. 

CAGLS,
The newer versions are going into production this month and will be going out to customers in September.  We are also going to offer this same pin for the CZ-97's.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: TX_Southpaw on August 23, 2013, 02:37:03 PM
September...great, I'll have time to save up some cash.  Maybe sell some stuff on Ebay and build up some Paypal bucks.   ;D

This is pretty much where I'm at, looking at changing firing pin and dropping spring weight.  Will these be extended firing pins, or just a factory replacement?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Bishop112 on August 23, 2013, 09:32:40 PM
You tha man David!
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: DCH2 on August 25, 2013, 01:06:26 AM
Nice, sounds like I will be placing an order with you in Sep!  O0
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: TX_Southpaw on September 17, 2013, 05:45:52 AM
Is there an updated estimate on these? Thanks.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: draftpick on September 25, 2013, 09:11:14 AM
+1. And where can I order one at?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Bishop112 on September 25, 2013, 02:26:17 PM
+1. And where can I order one at?

http://cajungunworks.com/
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: draftpick on September 25, 2013, 04:51:08 PM
+1. And where can I order one at?

http://cajungunworks.com/

Thanks!
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on September 25, 2013, 08:14:01 PM
It takes 6 full weeks to make a production run of 2,000 firing pins.  Then they have to be heat treated.  Production of the new FP's was completed a few days ago and they are off to heat treat.  I should have them very soon.

BTW, we are so confident in these new FP's I am probably going to offer a lifetime warranty.   They will be that good.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: TX_Southpaw on September 25, 2013, 09:54:17 PM
Wowwie Zowwie!!!

Are these extended firing pins or stock length?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on September 26, 2013, 08:33:05 AM
Extended only.  I will also finally offer a totally new, redesigned extended FP for the CZ-97 series too.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: TX_Southpaw on October 08, 2013, 07:46:20 PM
Are these available now?

I may not be first in line, but I'll be in line.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: CAGLS on October 10, 2013, 09:12:06 PM
Nice, David your not helping my CZ addiction. ;)
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: schmeky on October 24, 2013, 09:42:34 PM
Pic of new CGW "Perfection" firing pin.  Note how much thicker the tapered end is.  Stock pins break at the transition to the taper.  This S-7 steel, RC-45 heat treated firing pin will be virtually unbreakable, carrying the only lifetime warranty in the industry for a FP.   
(http://i81.photobucket.com/albums/j235/schmeky/NewFiringPin001.jpg)
Its' all in the details.  Notice the stock FP tip which has a very small impact area.  Notice how much more impact area the CGW "Perfection" FP provides. 
(http://i81.photobucket.com/albums/j235/schmeky/NewFiringPin004.jpg)
We are packaging these for distribution and use in all our products, SRS, Ultra-Lite, and bare firing pins available in November.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: BigHeat on October 24, 2013, 09:48:02 PM
Looks nice   Guess ill have to buy one, once they become available
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Bishop112 on October 24, 2013, 09:48:51 PM
Looks AWSOME! Great work as always my next CZ will have one of those... and if the Pins i have bought from you previously ever break the other guns will have them too.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: bradley cz on October 25, 2013, 12:01:52 AM
David is right, when i installed the defensive carry package on all three of my cz's.  Every roll pin that holds the firing pin in place had a little damage because of the design as stated above and soft material. I use a numberb#83 o-ring when I practic dry firing. Snap caps are a waste of money.
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Denzien on October 31, 2013, 10:33:02 PM
What is the purpose of an extended firing pin, and what else needs replacement or adjustment to avoid rupturing the primer cap?
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: 1SOW on October 31, 2013, 11:22:16 PM
Quote
What is the purpose of an extended firing pin
When you want a lighter DA trigger pull, decreasing the hammer spring weight is the main answer.  There is a limit to how light the spring can be and still be able to fire the primer.
Adding an extended firing pin and a lighter FP spring,  allows an even lighter hammer spring and can still fire the primers reliably.

Example"  in a full size 75, the hammer spring is 20# stock.  Changing to a 15# will likely still fire most primers reliably.

Changing to a 13# ( or maybe even less) hammer spring will still be reliable with an extended FP and lighter FP spring.

Hope this makes sense

 
Title: Re: Design Flaw in CZ OEM Firing Pin
Post by: Denzien on November 01, 2013, 12:46:02 AM
It does, thanks