CZ Open Build Theory

[snyder951]

Kneelingatlas was just looking at czc and saw something that may be up your alley.      https://czcustom.com/catalog/product/view/id/14139/s/czc-brl-thrd-9mm-ts/category/207/

 

[AcePrater]

Ace Race Bracket - Related to gun in theme of Open Poors... 

$14 at lowes and $59 from Ben Stoeger for the block. I had a detailed explanation on another site, but I think we all know what's goin on here so I will save the read.

 

Looking for opinions on the outside trigger guard. Right now the winning option is just another piece of angle bolted to the rearward facing flat bolted under the block

[paramajic4]

Awesome thread with lots of information. I'm still confused about a couple of things. I want to build an open gun from my 9mm TS. Why can't I just buy a longer barrel from CZC, thread it and and add a comp? It seems from the thread that the Comp will need clearance to fit inside the dust cover but I can do that myself. The primary role of this gun will be 3-gun open division. The option of using SP-01 slide and stock TS barrel makes sense but I haven't seen a bunch of these for sale. Which comp and where to get it? 

 

Thx

[AcePrater]

Welcome to the Poors! Go ahead and pour yourself a cheap beer and heat up some leftovers, you deserve it!
Your plan seems do-able. I think there needs to be some mechanical interference fitting to keep the comp from spinning out of time, which is the problem I have been having. I will defer to the others that have had greater success than I.

 

 

[AngeloConde]

49 minutes ago, AcePrater said:

Welcome to the Poors! Go ahead and pour yourself a cheap beer and heat up some leftovers, you deserve it!
Your plan seems do-able. I think there needs to be some mechanical interference fitting to keep the comp from spinning out of time, which is the problem I have been having. I will defer to the others that have had greater success 

Well sid I've been eyeing this thread for some time now still haven't brought myself to doing it

[AngeloConde]

On 12/20/2020 at 4:14 PM, paramajic4 said:

Awesome thread with lots of information. I'm still confused about a couple of things. I want to build an open gun from my 9mm TS. Why can't I just buy a longer barrel from CZC, thread it and and add a comp? It seems from the thread that the Comp will need clearance to fit inside the dust cover but I can do that myself. The primary role of this gun will be 3-gun open division. The option of using SP-01 slide and stock TS barrel makes sense but I haven't seen a bunch of these for sale. Which comp and where to get it? 

 

Thx

I belive the standard czechmate comp or idk if atlas is still doing it he was making some a while back

[AngeloConde]

On 8/7/2020 at 4:17 PM, Stdz said:

Has there ever been a competitive S2 in open ever made? It would have to be major. SO most likely 40 seeing how the S2 chamber is already short. I guess you could ream it. But that seems like a lot of reaming for the S2.

There was someone on the cz open shooters fb page that converted an s2 to open

[Ludde]

Something new for 2021

 

CZ Shadow 2 modified for Open division.

 

Shortened slide & frame.

Czechmate reverse plug.

Own designed comp, 2 first ports angled rearwards.

Own designed red dot mount inspired by Seboweapons model. Further rear, more thumbrest mounting options.

M-arms magwell.

Delta Optical Stryker 6 moa red dot.

Eemann tech large high safety trimmed down.

 

 

[AcePrater]

Whoa! very nice, is that a bushing comp?

I just got my pistola back from the smith - It's the same as it was when I dropped it off at Thanksgiving... Needless to say this has prompted me to get my own tap and die set and other tooling. I will be running open minor for now. it was good just to shoot the dang pistol again.

 

The Ace Race holster id great, it holds the CZ97 too.

Here's a pic and todos:

• grips interference with mag
• magwell
• racker
• RUN IT!!

[Ludde]

The tests continues.

 

Now I've tested 16, 18, 20, 22 & 24 lbs main springs also with both factory radius & prototype square firing pin retaining plate.

 

The videos here are with the factory radius fprp.

I did not like the feel of the square one it felt harsh in the beginning of the slide movement when it quite rapidly increases the main spring force compared to the radiused one.

 

In the description you will see the spring rates (20 & 24lbs) in these videos.

 

I settled for the 20lbs main spring it felt most controllable with this setup for the moment. Going through the video frame by frame both it is evident that both setups stays flat while the hammer is being cocked (comp is doing its job) and the gun stays flat until the slide hits the frame in its most rearward position.

During this anaylsis it is also clear that they both have pretty much identical flip up once the slide hits the frame.

The 24lbs main spring setups seems to have a little bit less vibrations coming back down as the slide returns.

 

With the 24lbs I felt like I had to really focus on my grip pressure and vrists not to let the gun rotate as the slide overcomes the hammer (at least that's what it felt like).

 

With the 20lbs I could be a bit more relaxed while still being close to the same muzzle rise as the 24.

I might also like the 24 if I would get enough practice with it and build more strength.

Once I get some more practice with this setup I might revisit and revise the setup.

Never ending story in Open Division, but that's the charm also.

 

20lbs

 

 

 

24lbs

 

 

 

Edited March 22, 2021 by Ludde

[AcePrater]

watching the brass fly in this vid just made my day- thx for sharing!

[Ludde]

Yep you guessed it, more testing done today!

Now I am running a 20lbs main spring, 11lbs progressive recoil spring @ 166pf 123grain RN.

 

In the transition segment I was focusing on letting the gun do its thing while observing the dot, the feeling and the behaviours of the gun rather than putting down all A's

 

 

[AcePrater]

looks like it shoots flat. The 20# mainsprings sounds stiff, as I always try to reduce those for triggers, but then sometimes get light primer strikes. I'm just curious as to how the stiff mainspring affects trigger and does it help with another aspect I'm not aware of.

 

I still dig that S2 setup, it looks killer. I hope you roast some TSOs or mates.

 

As far as the RDS mount goes that looks good. I see what your are saying about thumbrest options. It seems like you would get less dot bounce being over the dovetail as well but just speculating.

 

On your slide and frame did you just whack the end off flush to keep the comp from contacting the frame during cycling?

It's a great idea, but it would be hard for me to do to a $1500 gun. "I support your bubbaness by proxy"...

[Ludde]

9 hours ago, AcePrater said:

 

 

These are some of the things to consider when switching mainsprings.

First off the triggerpull (crispness of break & weight).

Depending on your hammer and sear engagement surfaces, mostly how "clean" or polished they are will effect the ammount off difference the mainsprings have when switching from light to stiff.
Personally I do not alter the angles of the surfaces, I believe that the CZ hammers and sears are only surface hardened and will wear if you start to really cut different angles into them.

I do not like a ultra light trigger (it makes it hard to prep the trigger on the fly, "No click banging here").

With the CZ SA hammer (TSO or Czechmate style), for me when switching from 16lbs main spring to a stronger one made my trigger feel a little bit gritty and creepy. I did not dislike the weight but the grittyness.

Currently I have a DA/SA hammer with the disconnector removed since this hammer has less engagement surface than the SA hammer the trigger pull weight and crispness was not negatively effected by the increase in main spring weight.
I tested even the 24lbs main spring and this produced a quite light and crisp break.

I also have a tanfoglio sear spring in my CZs to get a more well define wall before the trigger breaks.

Then the other positive thing with going up in main spring weight is that you can somewhat reduce the slide speed.
The increase in main spring weight will reduce the slide speed as it has to cock the hammer while it is starting to move rearwards.

In all my tests so far when analyzing the video footage frame by frame it is evident that the gun does not rotate upwards until the slide bottoms out on the frame. You can even se that when the compensator is working as the slide cocks the hammer the gun even rotates down a little bit by the effect of the compensator). Then how to limit the flip or rotation upwards when slide bottoms out on the frame... by reducing the slide velocity (and/or weight) by the help of the main spring (initial slide velocity) and the recoil spring (helps a little when it bottoms out on the frame).

Here are some examples of trigger pull weight (average of several slow consistent pulls).
This is with a CZ DA/SA hammer and Tanfoglio sear spring (to increase the defined wall before it breaks).

22lbs Main spring 680grams (1.5lbs)


20lbs Main spring 560grams (1.2lbs)


The SA only hammer increased the trigger weight by approx. by 150grams (0.3lbs) compared to the DA/SA one. Again I had nothing against going up to ~750grams in trigger weight but I did not like the grittyness that came with it. This might have been possible to solve with some additional polishing or worst case changing of angles.

Regarding the RDS mount and thumbrest options, I think it is a matter of preference and the real life result when shooting. Seeing how the dot tracks and returns. Not necessarily what "felt" good but more how effective or repeatable the result is. Having many mounting options allows you to tailor it for the best performance.

The frame was cut back ~6mm and the slide ~14mm, this is a combination around which I designed the comp and the relief cuts in the comp (rearward travel during unlocking) along with the length of the barrel extending past the slide etc.


 

 

[o27]

On 3/6/2021 at 5:54 PM, Ludde said:

Something new for 2021

 

CZ Shadow 2 modified for Open division.

 

Shortened slide & frame.

Czechmate reverse plug.

Own designed comp, 2 first ports angled rearwards.

Own designed red dot mount inspired by Seboweapons model. Further rear, more thumbrest mounting options.

M-arms magwell.

Delta Optical Stryker 6 moa red dot.

Eemann tech large high safety trimmed down.

 

 

 

How do you like/rate the Delta Optical Stryker? Being based in Europe myself, this looks to be similar to the FTP Alpha?

[Ludde]

9 hours ago, o27 said:

 

How do you like/rate the Delta Optical Stryker? Being based in Europe myself, this looks to be similar to the FTP Alpha?

In short, I like it. 

[Ludde]

Now I've finally designed, fitted and tested my new and improved compensator.
There are two main things that are changed compared to the first version.

First of I added a semi full profile to the comp in order to cover the reverseplug and most importantly keep the barrel from wobbling when goin in- & out-of lockup by adding the guide rod hole into the design (much like the oem czechmate comp).

The second thing and the big improvement in terms of compensating effect and softness.

I changed the port angles a little bit and extended the compensator upwards to make better use of the available gasses/forces.

This is working very well and is a big improvement compared to the ~4 different comps tested on the old shadow and the first model tested on the Shadow 2.

Here I am using 20 lbs main spring, 9 lbs recoil spring, 2mm buffer, 165 PF, 124gr AlsaPro RN, 3n38
 

 

 

 

 

[kneelingatlas]

That's fantastic Ludde!

[regor]

Big space gun aesthetics! Awesome work.

[Kirkster]

On 5/19/2021 at 5:22 AM, Ludde said:

Now I've finally designed, fitted and tested my new and improved compensator.
There are two main things that are changed compared to the first version.

First of I added a semi full profile to the comp in order to cover the reverseplug and most importantly keep the barrel from wobbling when goin in- & out-of lockup by adding the guide rod hole into the design (much like the oem czechmate comp).

The second thing and the big improvement in terms of compensating effect and softness.

I changed the port angles a little bit and extended the compensator upwards to make better use of the available gasses/forces.

This is working very well and is a big improvement compared to the ~4 different comps tested on the old shadow and the first model tested on the Shadow 2.

Here I am using 20 lbs main spring, 9 lbs recoil spring, 2mm buffer, 165 PF, 124gr AlsaPro RN, 3n38
 

 

 

 

 

 

What are you using for a racker.  I am a lefty looking for something to get the racker higher to stop the occasional thumb strike.  Most of the ones I have seen are righty ones that curve backwards on the left hand side of the gun and swapping them to the right makes them curve forward which I am not sure I would like that

[Ludde]

7 minutes ago, Kirkster said:

 

 

What are you using for a racker.  I am a lefty looking for something to get the racker higher to stop the occasional thumb strike.  Most of the ones I have seen are righty ones that curve backwards on the left hand side of the gun and swapping them to the right makes them curve forward which I am not sure I would like that

It is my own design, have designed both straight and forward angled ones. Currently I am liking the forward angled design.

[AcePrater]

Just catching up on this thread again. wow. that looks super cool Ludde...

Great work!

[Superkaratemonkeyfighter]

Amazing work. 
I like the middy length open gun look. 
it looks well balanced. 
seems like  the trend is getting away from the long full length slide and comp. 

I love to see the cz gun people experiment and improve the equipment like the 2011 have been. 

[DungFlinger]

Hi,

 

Any suggestions and thoughts for a 40SW factory ammo open CZ?  I'm a new shooter that got a pair of CZ P09's during the  pandemic.  I cant really see myself doing any reloading and load developments, so started looking at calibers that would put in the Maj power factor from of the shelf ammo.  it's hard to find open CZ's that fit this bill.   I love my CZ's and would like to help with getting more Open CZ guns in the mix at competitions.  I'm not a gunsmith or machinist but I do tinker enough with things that I wouldn't mind the work to make it work.  I have been looking at the TSO and TS2 prior to running into this forum.   I have not found any threaded barrels or compensators for them yet.  Thank you for all the insight and testing that's been done in this thread.. it's a wealth of info.  Just wondering if there's any new info in regards to a .40 cal. opens

[kneelingatlas]

1 hour ago, DungFlinger said:

Hi,

 

Any suggestions and thoughts for a 40SW factory ammo open CZ?  I'm a new shooter that got a pair of CZ P09's during the  pandemic.  I cant really see myself doing any reloading and load developments, so started looking at calibers that would put in the Maj power factor from of the shelf ammo.  it's hard to find open CZ's that fit this bill.   I love my CZ's and would like to help with getting more Open CZ guns in the mix at competitions.  I'm not a gunsmith or machinist but I do tinker enough with things that I wouldn't mind the work to make it work.  I have been looking at the TSO and TS2 prior to running into this forum.   I have not found any threaded barrels or compensators for them yet.  Thank you for all the insight and testing that's been done in this thread.. it's a wealth of info.  Just wondering if there's any new info in regards to a .40 cal. opens

 

If you're not reloading don't bother with the comp, just slap an optic on a TSO and Rock n Roll!  170mm pads from Springer plus CZC spring/follower should get you 24-25 rounds in your big stick.  If you love Open you'll buy a Czechmate and reloading press in no time!