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CZ Open Build Theory


kneelingatlas

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1 hour ago, kneelingatlas said:

 

Your barrel is treaded 1/2x28, right?

 

If so this would be worth trying:

 

https://stores.sjcguns.com/sjc-major-9mm-11-port-aluminum-compensator/

I am a bit confused, 11 port compensator would work with factory ammunition? I thought I would need less ports! Like one or two ports in all...for reliable function 

Can you explain a bit please. 

 

Yes, I do have 1/2x28 threaded barrels.

 

Edited by coolbox
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3 hours ago, MoRivera said:

Have you also considered shooting softer 147 rounds?  I get them (in normal times) from Fenix ammunition.  Great load for steel/plates/knockdown.  I also have a longside SP01.

 

image.thumb.png.b42f51b85b99e3d03df4f7a7a3b5cf21.png

That is very nice, I recall appreciating this particular pistol on another CZ forum.

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17 hours ago, coolbox said:

I am a bit confused, 11 port compensator would work with factory ammunition? I thought I would need less ports! Like one or two ports in all...for reliable function 

Can you explain a bit please. 

 

Yes, I do have 1/2x28 threaded barrels.

 

 

In general, factory ammo uses powders on the fast side of the scale, producing dramatically less gas than hand loads tailored for use with a comp, so the effect of a comp is minimal what shooting factory loads, but more ports will certainly not hurt performance.

 

Over the past eight years I've shot every gun/comp/hole/length/powder/bullet combo I could get my hands on any I have never been impressed by small comps with small ports.

 

With everything I've done, here's what I shoot:

 

IMG_20180702_211853-1503x1838.thumb.jpg.6731a65ace8f6edbe41136c7f10592ae.jpg

 

I giant aluminum comp/no holes in the barrel, 10.5gr of Shooters' World Major Pistol under a 115gr Montana Gold CMJ.

Edited by kneelingatlas
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12 hours ago, kneelingatlas said:

 

In general, factory ammo uses powders on the fast side of the scale, producing dramatically less gas than hand loads tailored for use with a comp, so the effect of a comp is minimal what shooting factory loads, but more ports will certainly not hurt performance.

 

Over the past eight years I've shot every gun/comp/hole/length/powder/bullet combo I could get my hands on any I have never been impressed by small comps with small ports.

 

With everything I've done, here's what I shoot:

 

IMG_20180702_211853-1503x1838.thumb.jpg.6731a65ace8f6edbe41136c7f10592ae.jpg

 

I giant aluminum comp/no holes in the barrel, 10.5gr of Shooters' World Major Pistol under a 115gr Montana Gold CMJ.

Thank you. 

I can cosnider that for steel, when shooting double handed.

I would also want a smaller brake for single hand matches, if you can advise one that still works despite being small!

What recoil spring with factory 9mm loads? Currently using 15lb (double hand shooting) and 18lb (single hand shooting). 

 

 

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  • 4 weeks later...

Update on my projects progress.

 

Own designed aluminium compensator.

Wolff 16lbs main spring and 11 lbs recoil spring.

 

Back to Shadow original strength extractor spring.

 

In this video the splits clocked .16-.17s

 

Still on 8.2grain VV3n38 ~168pf

 

 

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  • 3 weeks later...

day late dolla dolla short...

looking for this comp - as listed up there^^^ https://stores.sjcguns.com/sjc-major-9mm-11-port-aluminum-compensator/

so called SJC customs and N/A

called shooters connection and they said they no longer distribute SJC so what they have is it. They have the 5 port but that's all, they do have 40 cal 11 port - pass.

I'm also working on getting some machining tools and very interested in making a comp. and other parts.

If there is a good book or resource on comp milling and comp design please advise.

 

Update.. called SJC and guy answered very knowledgeable good service so I put in the order. he said they have had many of these in service useing the red locktight with no set screws. He said set screws can misalign the bore and cause baffle strikes because its so long.

 

Working on load Dev this weekend. New custom seating stem for the 124 PDs should be in tomorrow - stuff coming together!

 

 

Edited by AcePrater
update on comp
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On 2/9/2020 at 2:35 PM, RonnieJr said:

Sp01 open build update. I decided to switch comps. I went with the SJC 11 port. I was running a 3 port steel comp previously. I am very pleased with the SJC. Super flat with 9mm major. My previous comp, I notched the comp to clear the frame. After much head scratching I decided to notch my frame for the SJC. It came out very clean. 

IMG_3771.JPG

IMG_3772.JPG

 

 

Ronnie Jr.

I'm looking at this setup now that I have threaded barrel and the same 11 port SJC comp in hand.

Did this work out for you? idd you have any issues with the comp coming out of time? did you use the red threadlocker?

I'm curious as to why you clearanced the frame as opposed to clearancing the comp?

I'm considering just milling off the bottom corner nubs, and then take some off the mounting face so it times correctly (maybe with a thin washer or two).

 

I WAS thinking that I could just fab some guide flats that mount to the pic rail and keep the square profile from rotating, but I had it in my head that the SJC comp had a larger "belly" section that the guide would slide on. turns out that would be a bit of a stretch though.

 

I just got my bullets of choice and am working on some Power Pistol loads this past weekend. I can tell they are superior to what I was shooting and I'm not close to major yet.

Thanks again for the insight!

 

 

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I am sorry if this has already been asked.. but this topic is just an overload of information! 😅

 

I got two TS’s both in 40.S&W, and i am considering to build one of them into a ipsc open gun. And i,want it as cheap and easy as possible. It doesn't need to the best solution, just a reliable solution 👍 I am not allowed to have +20 mags here in Denmark, so i can easily use my 40’s for major, and not be concerned about magazine capacity... i am not allowed to have 28-29 shot mags anyway 😖

 

If it turns out that i like the open division, then i think i might sell one or both of the TS’s and buy a czechmate. Therefore i would like not to cut either my frame or slide. 


I have seen (in this topic) people using SP01 slides and a comp. Can i simply just get a SP01 slide, thread my TS barrel and mount a bull style compensator?  Or is it more complicated than that? 
 

 

 

 

 

 

Edited by Rasmilling
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1 hour ago, Rasmilling said:

I am sorry if this has already been asked.. but this topic is just an overload of information! 😅

 

I got two TS’s both in 40.S&W, and i am considering to build one of them into a ipsc open gun. And i,want it as cheap and easy as possible. It doesn't need to the best solution, just a reliable solution 👍 I am not allowed to have +20 mags here in Denmark, so i can easily use my 40’s for major, and not be concerned about magazine capacity... i am not allowed to have 28-29 shot mags anyway 😖

 

If it turns out that i like the open division, then i think i might sell one or both of the TS’s and buy a czechmate. Therefore i would like not to cut either my frame or slide. 


I have seen (in this topic) people using SP01 slides and a comp. Can i simply just get a SP01 slide, thread my TS barrel and mount a bull style compensator?  Or is it more complicated than that? 
 

 

 

 

 

 

 

Yes, like this one.  It uses a small frame Tanfoglio comp:

 

21056113_1803628006318790_82401675604509

 

Tanfoglio makes an aluminum three port .40 comp, let me know it you have trouble sourcing one in Europe 😉

 

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25 minutes ago, kneelingatlas said:

 

Yes, like this one.  It uses a small frame Tanfoglio comp:

 

21056113_1803628006318790_82401675604509

 

Tanfoglio makes an aluminum three port .40 comp, let me know it you have trouble sourcing one in Europe 😉

 


Yes! Exactly like that 😜 
 

But just to be sure. 
 

You haven't done anything else, than getting a SP01 slide, a comp and threaded the barrel?

No major fitting, no cutting etc. ? 
 

Edit: oh... and a reddot ofc. ! Got a Leupold DPP on my open revolver i want to use. 
 

If you already have a link to a comp, that would save me some google time 😁

 

Edited by Rasmilling
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I would think that you could either thread current fitted barrel - or buy a threaded barrel which most likely would have to be fitted. My threaded SP-01 replacement barrel did require fitting and I would not call it easy. Good luck!

 

I've just emailed the normal places (first page results of google) and asked for in stock Czeckmate revers plug and guide rod and no on has them so far...

Edited by AcePrater
update on parts avail.
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48 Recoil Spring Guide Casing from this diagram.

https://cdn.cz-usa.com/hammer/wp-content/uploads/2014/04/75_TS_Czechmate_en_06-2012_web.pdf

 

CZ-usa mentioned this:

We do generally carry that item however it is currently out of stock. The part number is 315047000002 on our Webstore and is $50.00 before tax and shipping.

 

 

I'm still a bit fuzzy on how/if the slide would need to be clearanced to use one of these. Is it a drop in and go or need milling/fitting.

 

Has anyone threaded the end of the guiderod to accept a nub that would keep the comp from coming OOT?

Just ponderings...

 

 

 

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39 minutes ago, AcePrater said:

48 Recoil Spring Guide Casing from this diagram.

https://cdn.cz-usa.com/hammer/wp-content/uploads/2014/04/75_TS_Czechmate_en_06-2012_web.pdf

 

CZ-usa mentioned this:

We do generally carry that item however it is currently out of stock. The part number is 315047000002 on our Webstore and is $50.00 before tax and shipping.

 

FYI, those have been out of stock since at least December and every time I contacted them they said "they are coming in next month's shipment". CZ-USA does not seem to want people to make their own open uppers, so they keep a lot of the Czechmate-specific parts unlisted or rarely in stock. 

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2 hours ago, AcePrater said:

48 Recoil Spring Guide Casing from this diagram.

https://cdn.cz-usa.com/hammer/wp-content/uploads/2014/04/75_TS_Czechmate_en_06-2012_web.pdf

 

CZ-usa mentioned this:

We do generally carry that item however it is currently out of stock. The part number is 315047000002 on our Webstore and is $50.00 before tax and shipping.

 

 

I'm still a bit fuzzy on how/if the slide would need to be clearanced to use one of these. Is it a drop in and go or need milling/fitting.

 

Has anyone threaded the end of the guiderod to accept a nub that would keep the comp from coming OOT?

Just ponderings...

 

The Czechmate recoil spring housing drops right into a 9mm TS slide, however the result is a slightly shorter stroke than the Czechmate so if you want the same or more, you have to remove some metal.

I've never threaded a guide rod, but I have drilled and tapped a cut slide, then glued in a set screw with the center drilled out for the guide rod; it was not fun and I don't recommend it.

If you're looking for those Czechmate specific parts, send me a PM, I might have some extra.

 

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Saving someone the hassle if they want to go that route of the reverse housing /plug. Here is the best chance I could come up with in the US. It is a link where you can sign up to be notified when the part is in. Can not pay for the part beforehand, only be notified.  I skipped it because of reasons below...

https://shop.cz-usa.com/SearchByKeyword?word=315047000002

 

Since that will require milling, and a Tac Sport slide, I'm skipping that option for now. 

 

I've made just a tiny bit of progress that shows promise, I think...

So I couldn't screw the comp on far enough to seat on the barrel bushing because the guide rod was just about 1/16" too long. I "clearanced" it to be just a little short. What this allowed me to do was screw the comp on the rest of the way and see what needed to be cut off the bottom corners of the SJC 11 port comp. It looks like it will fit in the frame with just a bit of simple file work.

 

Thanks for the offer on the reverse plug, but I'll pass for now.

 

I did also speak with a local open gunsmith and he said he uses guns with bull barrels and finer threads and locktight and sometimes set screws.

 

--------Edit----------

I guess I'm not saving anyone any hassle if those have been out since Dec.

 

Edited by AcePrater
just read updated post
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Took some filing, but it clears - polished dog turd, but whatevs, it clears. I'm wondering if it might help to have a thin brass spacer washer to time it just right, but looks like too much trouble. It would have to be very small and fitting would be a PIA(taking washer on and off and filing between times). I'm off to get some red lock-tite in the AM and with any luck, if it's not drenched this weekend, start out with limited rounds and see how she goes.

clearance1.jpg

clearance2.jpg

clearance3.jpg

clearanceStock.jpg

openPoorsLeftSide.jpg

radius1.jpg

timeStock.jpg

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1 hour ago, AcePrater said:

124PDs over Alliant Power Pistol for major - considering other powders. load on D650.

 

#1 on that list is what I shoot: 10.5gr of World Shooters Major Pistol under a 115gr MG CMJ. Best load available if you ask me 😁

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On 5/18/2020 at 5:29 AM, kneelingatlas said:

Tanfoglio makes an aluminum three port .40 comp, let me know it you have trouble sourcing one in Europe 😉

 


Greats thanks to Atlas for helping me out with the comp! It is on its way from US to Europe 🤠

 

I have just ordered a new magwell, grips, red dot mount and thumbrest, all from Seboweapons. 
 

“Only” thing i need now is a SP01 slide... which may be a bit harder to find. I think i will have more luck in finding a used SP01 and use it as a donor. 

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Well, my first try was a failure, I quit, going back to stock glocks...

 

mmmkay..

4 limited minor shots into testing it was out of time. I think I know why and I think I have a new plan. I think the way I sloped the profile of the relief on the comp it would still run, but be held at that point that is ~4 out of time. doesn't matter cause it will be addressed.

 

The reason - When I dry fitted the comp it started to lock up on the threads when the comp was about 180 degrees from where it needed to be, the top vents were pointing almost straight down. When thinking about the final fit, I though about torquing it down in addition to thread sealer, but thought(what if I get 1/2 way to where the vents are pointing around 10 oclock and it locks up? Then I'm pretty fubared. I decided to unthread it 1/2 turn to time it and set the locktite. lasted 4 rounds.

 

The possible solution - get the thing the rest of the way off, degrease and such. Then check timing. I have an idea I want to share about timing. To increase/adjust timing, there are 2 things I think could be done. 1) add thin brass washer 2) lap the face of the comp and grind it down until it times and load properly.

1) would be an easy 2nd try IF the correct washers could be suggested/linked to - can I use the same ones for muzzle break timing adjustment? I'm not good with ARs ironically.

2) this would almost be like a valve lap job. I've got all the compounds and am sure I could rig something up to provide enough force to polish it down just a bit.

 

What do you guys think/suggest? Either way I need to get some high temp loc tite on the way. I found out that even the red locktite and red permatex are only good up to about 300 deg. but the specific high temp lock tite is good to good to 450.

 

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18 minutes ago, AcePrater said:

The possible solution - 2) lap the face of the comp and grind it down until it times and load properly.

 

You're overthinking this, a file or sandpaper will work just fine.  The gap between the slide and comp should be big enough to see daylight through it, if you try to make it too tight, the slide will impact the comp during firing and break it loose on the threads.

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There is still a gap between the comp and the barrel bushing.

The gap was there when it was timed correctly and is still there. 

What I believe is happening is that the shoulder face of the extended threaded barrel is mating with the face of the counter bored comp, so my plan is to try lapping the face of the comp, which is about 1/2" deep into the body of the comp.

 

I bet a .40 cal chamber reamer would do it properly.

 

Of course the HF heat gun is toasted, so we will see this weekend. If it wont get it up to temp to ease the thread locker I have an oven and welding gloves in the garage. I don't want to play hot potato with it unless I have to.

 

I'm debating having the chamber reamed while I'm in the middle of attempts.

 

I still had a great time at the range. I won't clog this thread up too much with that but I got my first 10/22 and shot it and the Ruger slabside(still my fav plinker). Used chrono for the first time to data handloads and the old 75B at plenty of ammo.

 

Updates to come. Thx for the prodding. it is fun.

 

 

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