Author Topic: How to achieve the perfect DA trigger pull on your CZ 75  (Read 828 times)

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Offline Mercs

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How to achieve the perfect DA trigger pull on your CZ 75
« on: September 24, 2020, 10:19:18 AM »
Have you finally finished fitting your new custom disconnector for short reset, or for short reach, and now you find you have a DA pull that isn’t as controllable as it was to begin with? Did you make this face after the first test of the new DA trigger pull:


Have you dropped in a new disco and afterwards find your DA pull is “stagey”? When dry-firing in DA, do you find you are driving the front sight down because the trigger is jerking back after the break? Are you having to go up in main spring weight to consistently light off primers in DA, that would otherwise be GTG in SA mode?

All of these problems are symptoms of just ONE issue with the dimensions of your disco....

If I were a gunsmith, I could probably make a bunch of money doing trigger jobs for these guns. However, I am not a professional ‘smith by any stretch. I have merely learned this trick from one haha.  If you can fit a disco for short reset, than you will also have the skills to do this tuning yourself.

Anyways this is like those internet ads where it says “use this ONE TRICK to blah blah blah”, but this time it’s for real!

THIS WILL NOT AFFECT SA TRIGGER PULL OR RESET, ONLY CHANGES THE DA.

I see many similar posts over the years describing the symptoms in the opening paragraph of this post. I almost always see someone chime in to try to help by talking about the wings of the disco, and then this ultimately leads down a rabbit hole of unnessary alterations to the disco that will mostly just create problems with your guns timing and/or trigger pull. STOP. DO NOT TOUCH the wings on your disco.

Here goes. When the DA stroke is occurring and your disco is being pulled back NOSE DOWN by the trigger bar, the nose can bottom out prematurely on the ledge that is built into the frame. The harsh letoff of the hammer in DA mode is actually the disco binding with the trigger bar contact points as it slips off.



So what is happening here is your DA stroke is being shortened due to the pressure being exterted on the nose by the ledge. This often creates a harsh DA break, which can make you overdrive the pistol front sight down and miss follow up shots. I found this to be most apparent when doing short-reach trigger mods, both CZC and CGW varieties. Sometimes it just ruins the DA pull, and competition shooters in production class need a good DA pull for certain - but anyways, who among us doesn’t want THE BEST trigger pull for our CZ?

Here’s what you need to do. First, BE CAREFUL! You can turn your disco into trash by going to far with the DA tuning! Ye be warned!

What you are going to do, is to first ENSURE THAT YOUR TRIGGER BAR SPRING IS FULLY SEATED in the bottom grooves of the trigger bar on both sides and that it has even pressure and is in good condition. You will need this to be in good order for the tuning process, or you will end up with poor results. An improperly seated trigger bar spring alone will cause problems with the trigger press, so this always good to check first anyways before proceeding with any modifications.

Now that that’s out of the way, you will want to  trim down (file, sand, dremel, your pick) the nose of the disco (see my poor graphic depiction of this below). You will want to maintain the same roundish profile of the nose while doing so.


By shortening the nose, you will be allowing the trigger bar to pull back farther in DA mode before the hammer is released. You will increase your hammer travel in DA mode, which will increase its potential energy and negate the use of stronger main springs. Be conscious of your triggers position inside the trigger guard at the break point. This will also move farther back as you remove more material from the nose. You can achieve the original long, smooth DA pull which makes the CZ 75 so controllable and fun to shoot. You can make it even better, actually. However you must only do this a few thousandths of material and test, because if you take too much off, the hammer will go all the way back and will not drop at all in DA mode! So test often, get it to that sweet spot, and then leave it alone!

You can achieve perfection by measuring from the tip of the nose across the disconnector with a caliper, and taking off precise amounts.  Again, being careful not to go too far. It sounds scary, but the results will be well worth it when you get it right. Also, you can even do this without removing the hammer and assembly & mainspring, so it’s easier to test in-between.  If you just remove the sear cage and then hold up the disco with a punch, long sturdy tweezers or something, you can expertly file it down with a diamond dremel bit while avoiding the frame and other parts (not recommended, may scratch pistol or parts).

When finished - don’t forget to polish the nose of the disconnector and also the ledge on the frame, for maximum smoothness of the DA pull. When you get this mod right, you will achieve true bliss.

Please let me know if I left anything out or if I have made any errors in my post. I just wanted to get this out to the masses here because I’ve seen this same problem over the years, and I just want to help people avoid going down the wrong path and carving up their discos. Enjoy!


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« Last Edit: September 24, 2020, 07:17:25 PM by Mercs »

Online Tok36

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #1 on: September 24, 2020, 11:52:46 AM »
Thank you for the post Mercs. Interesting stuff. You mention that the disco can worked on while still installed. I assume that you mean to say that you can do so with the Sear Cage out of the frame?
Will work for CZ pics! (including but not limited to all CZ clones)

Offline Mercs

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #2 on: September 24, 2020, 12:07:36 PM »
Thank you for the post Mercs. Interesting stuff. You mention that the disco can worked on while still installed. I assume that you mean to say that you can do so with the Sear Cage out of the frame?
Excellent point , thank you Tok. I just edited that part to fix it


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Offline timmy75

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #3 on: September 24, 2020, 02:13:25 PM »
thank you for your effort to write this. i will try it ASAP. this should be pinned thread

Offline ITSSOCZ

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #4 on: September 26, 2020, 12:29:49 PM »
Great information.  Much appreciation for sharing!

Offline Mercs

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #5 on: September 26, 2020, 01:47:33 PM »
Let me know how it goes for you guys.  You can dry fire after each fine tune and you will notice more and more control with your DA trigger pull, until you get to bliss


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Offline timmy75

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #6 on: October 01, 2020, 06:24:43 AM »
this is how my disconnectors look



any advices before I take file and dremel?

Offline Philipl

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #7 on: October 01, 2020, 06:31:31 AM »
You could buy one from Cajun Gunworks:

https://cajungunworks.com/product/1485t2-disconector/

Offline Mercs

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #8 on: October 01, 2020, 07:33:16 AM »
this is how my disconnectors look



any advices before I take file and dremel?
Just take off a little each time, and test it out so you don’t take off too much. If you aren’t measuring, you can use a permanent marker to mark the nose of the disconnector. That way you know you are only taking off a little material each time and you can keep it nice and even


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Offline timmy75

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #9 on: October 01, 2020, 07:58:17 AM »
Interesting that good one is 0.2mm (1/64) longer than bad one..is that normal?

Offline Mercs

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #10 on: October 01, 2020, 08:05:07 AM »
Interesting that good one is 0.2mm (1/64) longer than bad one..is that normal?
Aren’t you trying to improve the DA on the new disco (left) to match the original disco (right)?


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Offline timmy75

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #11 on: October 01, 2020, 08:30:30 AM »
Interesting that good one is 0.2mm (1/64) longer than bad one..is that normal?
Aren’t you trying to improve the DA on the new disco (left) to match the original disco (right)?


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stock shadow 2 disco is left one ("good"), new disco is right one ("bad"). im trying to improve DA in right ("bad")

Offline Mercs

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #12 on: October 01, 2020, 08:49:33 AM »
Interesting that good one is 0.2mm (1/64) longer than bad one..is that normal?
Aren’t you trying to improve the DA on the new disco (left) to match the original disco (right)?


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stock shadow 2 disco is left one ("good"), new disco is right one ("bad"). im trying to improve DA in right ("bad")
Looking closer at your new disco, I have not seen one like that before. Who makes that one, and what is it doing when it’s installed in the gun? Is it shortened DA stroke?


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Offline timmy75

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #13 on: October 01, 2020, 12:24:18 PM »
Interesting that good one is 0.2mm (1/64) longer than bad one..is that normal?
Aren’t you trying to improve the DA on the new disco (left) to match the original disco (right)?


Sent from my iPhone using Tapatalk

stock shadow 2 disco is left one ("good"), new disco is right one ("bad"). im trying to improve DA in right ("bad")
Looking closer at your new disco, I have not seen one like that before. Who makes that one, and what is it doing when it’s installed in the gun? Is it shortened DA stroke?


Sent from my iPhone using Tapatalk

It is OEM CZUB sport disconnector from shadow 2 orange. this is version with shortest pretravel and very short reset. reset is very nice.
DA stroke seems the same length as stock, but in 3 stages and gritty. with stock disco DA is smooooth, but it has longer reset. i would like to achive smooth DA with this disco.

Offline Mercs

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Re: How to achieve the perfect DA trigger pull on your CZ 75
« Reply #14 on: October 02, 2020, 01:07:03 PM »
Interesting that good one is 0.2mm (1/64) longer than bad one..is that normal?
Aren’t you trying to improve the DA on the new disco (left) to match the original disco (right)?


Sent from my iPhone using Tapatalk

stock shadow 2 disco is left one ("good"), new disco is right one ("bad"). im trying to improve DA in right ("bad")
Looking closer at your new disco, I have not seen one like that before. Who makes that one, and what is it doing when it’s installed in the gun? Is it shortened DA stroke?


Sent from my iPhone using Tapatalk

It is OEM CZUB sport disconnector from shadow 2 orange. this is version with shortest pretravel and very short reset. reset is very nice.
DA stroke seems the same length as stock, but in 3 stages and gritty. with stock disco DA is smooooth, but it has longer reset. i would like to achive smooth DA with this disco.
If you’re sure that it is longer, maybe just try to polish the nose smooth, instead of filing


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