Making Magic - Cajunizing the Pre-B.

[Birds Away]

This thread will be about upgrading my transitional pre-B with parts from Cajun Gun Works.  What we want to attempt to show is the reduction in trigger pull weight with each step in the process.  I acknowledge that trigger pull weight is not the be all and end all of a gun.  There are elements of the trigger pull that cannot be quantified by numbers.  I would also like to acknowledge my good friend, llh1956, who will be doing all of the grunt work making all of the upgrades, doing the polishing and tuning and taking the pictures.  He is not a professional gunsmith.  He's just a guy like me who loves CZs.  Unlike me, he actually has some mechanical inclination and is able to actually keep track of all of these little parts and can ensure they end up where they are supposed to.  He has performed these upgrades on probably 6 to 8 guns for me and a similar number for himself and his results have always exceeded my expectations.  Our arrangement is that he performs these upgrades for me and I purchase extra parts for use in his guns.  Works out great for both of us.  So without further ado...


I purchased this CZ 75 transitional pre-B on Gunbroker.  Total expenditure for the purchase, shipping and transfer was $360.
We took her to the range on Tuesday evening and did some test firing.  This gun is well-used but not abused.  She functioned fine with no problems with feeding, ejecting, etc.  I used Blazer Brass for the tests and my only comment was that, for a couple of guys in their 50's, the stock sights have seen better days.  This will be fixed in time.  Other than that the gun was as accurate as you would expect for this model and although the DA was long the SA was shorter than I expected.  I suppose that is from extensive use.  Anyway, after the test fire llh1956 put the gun on the trigger gauge. He did the 10 pull average using a Lyman Digital Trigger Pull gauge. With the stock mainspring single action was 4Lbs 8oz, He then installed the CGW 11.5 mainspring and the average of 10 pulls was 3Lbs 15 oz.  Having a sub 4# pull by only changing the mainspring surprised both of us as we are used to doing upgrades on newer guns.  So this should be interesting.  Here is his photo of the gun broken down.

I will post the steps he has planned here, hopefully, later today.  This should be interesting and I hope you all enjoy the thread.

[ThompsonCustom]

Nice, any idea on what all he is going to do? If so you should list it and mark them off one by one or is he just gonna keep going until you get the desired trigger pull your looking for.

Also any plans on competing with this gun? If not that opens up some more parts and mods.

[Birds Away]

Yes, I am going to post the list later today.  I sometimes forget some of the parts so I wanted to check with him and make sure I had it all covered.  I am planning to compete with this gun.  I know many will say that it is illegal and they are correct.  Let me say that I compete for fun and with my skill level I am in no danger of beating any dedicated competitive shooters.  Where we shoot does not do an inspection of the gun.  I pay my $20 and shoot the courses with some friends and relatives.  We have a good time and always finish well within the bottom half.  If they tell me I have to shoot in a different class I won't really care because I am shooting against myself.  My accuracy is very good but my speed is not.  I want to see incremental improvement and I have so far. 

[ThompsonCustom]

Sounds like the best of both world's to me, every upgrade still on the table but your working towards improving your skills. I'm off to work now was just curious what all was going to be on your list, if you don't mind when I get home later tonight I'll/others will look over your list and add anything we can thing of.  This could get you in trouble tho it might be a mile long.

[Birds Away]

The following upgrades are planned:  Polishing the action, installation of new disconnector, race hammer, adjustable sear, extended firing pin, reduced power firing pin spring, reduced power trigger return spring, removable trigger pin, 85c trigger and an 11.5# mainspring.  This will include all of the associated pins and springs which are associated with these parts.  I intend to also add a F/O front and EZ drift rear sight.  Oh, of course, she will soon be sporting Hogue wraparound finger groove grips.

[Birds Away]

Next step is polishing the internals, reassembly, and then put it on the gauge again.  Results later.

[Birds Away]

My friend llh1956 spent some time Saturday polishing all of the internals.  I was surprised, as was he, that when he put it on the gauge after polishing the numbers were the same as before.  There was no change at all.  I attribute this to the fact that the gun is well-used and appears to have been fired quite a bit.  He said that some of the parts were rough and took a good deal of polishing.  So, now I am not sure.  Anyway, he will be installing the parts this week so I guess we will see.

[ThompsonCustom]

hmmmm that does seem a little odd. What did he use polishing? dremel or sand paper and if polish what it he use or what grit on sand paper. What all did he polish? I guess if all the part are worn into each other enough then it might not make any difference.

Added: here's a couple tips that aren't commonly thought of, Tweak the sear spring it will light the SA, Tweaking the trigger return spring if you go to far the trigger will not reset in double action, you trade a little return time for a lighter pull, I like to run a polish tool steel # 13 pin and fit a # 19 pin. The 13 is the pin that goes through the sear I think a polish hardened tool steel pin better than the stock one but I've never put a gauge on it. The #19 pin holds the hammer pin in place but if you fit a tool steel one you can stabilize the sear cage with it. I boil mine in sulfuric acid to turn it black that way it looks stock.

[Birds Away]

He installed all the parts in the lower last night.  After installation she is at 2lbs 4oz SA and 6lbs 10oz DA.  He said there is virtually no take up in SA whatsoever.  I am going to take my B in and see how they feel side by side.  He seemed to be very excited with the SA.  These guns are so funny.  You never know how they will come out.  My Phantom has a DA like that.  There seems to be no rhyme or reason why one gun ends up with a 6lb pull and one barely gets under 7.  Of course, when shooting, I doubt most folks would be able to tell much of a difference.  Hoping to get her to the range maybe Thursday or Friday. 

[Birds Away]

Not sure if anyone is still following this thread but here goes.  llh1956 disassembled the pre-B, as can be seen in the preceding pics, and did all the polishing according to the instructions in Schmeky's polishing thread.  As I said previously, when reassembled, the SA trigger averaged 2lbs 4oz and the DA averaged 6lbs 10oz.  While going through this process he realized that if he racked the slide the hammer would not release when the trigger was pulled but if he thumbed the hammer back it released just fine.  It also functioned fine in DA. Kind of perplexing.  He checked it out pretty thoroughly to see if he had overlooked something during reassembly and couldn't determine what the problem was.  So he gave Schmeky a call.  After checking a few things and a few questions and answers back and forth the culprit was discovered.  It turns out that the pre-B and B models differ slightly and the new disconnector will require some "fitting" in order to function correctly.  So, now armed with detailed instructions, llh1956's next step, after acquiring the correct Dremel attachment, will be to remove a little here and there on the disconnector to ensure a good fit.  The good news is that Schmeky says that, once the disco is properly "fitted" the trigger should be incredible. 

[llh1956]

As Birds Away posted I followed schmecky's thread for Smoothing the Action which is very informative, at the top of the CZ Home Gunsmithing. After finding the problem with the hammer, sear not engaging when racking the slide and a call to schmeky to find out that fitting of the sear will be necessary, my next step is to buy a diamond type grinding wheel to use in my dremel. Then the process of removing .010 at at time and testing for hammer, sear engagement. When the proper amount has been removed and hammer sear engagement are set the last step is to smooth with 400 grit paper wrapped around a 1/8" steel rod. Going slow to finish fit and checking. This is to fit the single action side of the disco. If I have trouble with the double action that will be another tutorial by schmeky.  After intial polishing and assembly and acheiving a 2lbs 4oz single and 6lbs 10oz double I do not find it necessary to the  change hammer and sear cage pins as I polished them while chucked up in the dremal.

[Birds Away]

^^^^See, he does exist.  You guys were beginning to wonder...

[llh1956]

So far I have done complete action polishing and installed every CGW part available on guns for Birds Away. PO6, 75 B all but no reach reduction kit, Phantom, Rami, PCR and currently working on the Pre B. All are awsome to shoot!! On my CZ's I have nearly completed everything on a Compact and Tactical and a SP-01 Shadow. After finishing them I recently purchased a 97B that will get the full polishing and CGW goodies installed. It will be converted to single action only

[jdubya87]

So far I have done complete action polishing and installed every CGW part availabe on guns for Birds Away. PO6, 75 B all but no reach reduction kit, Phantom, Rami, PCR and currently working on the Pre B. All are awsome to shoot!! On my CZ's I have nearly completed everything on a Compact and Tactical and a SP-01 Shadow. After finishing them I recently purchased a 97B that will get the full polishing and CGW goodies installed. It will be converted to single action only

I'm rolling with that PCR you did. Its very nice.

I'm excited to see the potential of the pre B pistols. I'm curious to see what the final pull weight is once all is done.

[llh1956]

So far I have done complete action polishing and installed every CGW part availabe on guns for Birds Away. PO6, 75 B all but no reach reduction kit, Phantom, Rami, PCR and currently working on the Pre B. All are awsome to shoot!! On my CZ's I have nearly completed everything on a Compact and Tactical and a SP-01 Shadow. After finishing them I recently purchased a 97B that will get the full polishing and CGW goodies installed. It will be converted to single action only

I'm rolling with that PCR you did. Its very nice.

I'm excited to see the potential of the pre B pistols. I'm curious to see what the final pull weight is once all is done.

Thanks alot ,I'm glad you like my work!!