PDA

View Full Version : CZ75 D Compact Competition hammer install



coolbox18
28-11-2011, 02:58 PM
The decocker models in CZ family are one of the most difficult pistols to handle in gun-smithing. The sear cage and decocker assemble pops open, and requires a lot of patience, skill, and patience again, to re-assemble.

Unfortunately, the weapon I was modifying was NIB, had very tight springs and pin-holes. This meant I had to go the conventional way, let everything pop open instead of pushing longer sear pin out with a shorter slave pin. For those not aware of CZ P01 design, the sear cage pin holds the sear cage in the frame, as well as 3 different springs, sear, firing pin lifting block lever, and decocker assembly. One single pin goes through all these parts, and in the frame. A shorter slave pin will retain all the parts, while remove the sear cage from the frame to get to the hammer.


SEQUENCE
-Field strip
-Remove grips
-Remove main spring retaining plug and mag brake. This will lead to main spring popping out. This part can also be done after removing sear cage.
-Lift sear spring and remove decocking lever
-Remove washer which retains the sear cage pin.
-Push out the sear cage pin. The springs and other parts will literally fly out. Make sure you have them secured. If a slave pin were used, properly, you could have an intact sear cage coming out, no fuss.
-Remove the hammer pin retaining pin, and then the hammer pin (yes, a lot of pins)
-Hammer and disconnector are all yours to have now! The pins attaching the hammer and disconnector to the strut do take a lot, a lot, of beating to come out. They are very well staked. They will have to be replaced, so have them in spare beforehand.
-Re-assemble in reverse order.


TOOLS
-Punch (roll pin) 1/16", 3/32" , 1/8"

-Polymer hammer for smacking in the sear cage pin

-Starter punch kit

-The handle of the hammers for pressing down the plug, or any thing that does not damage finish, and can be used to hold/push the plug inside.

-Nose pliers

-Spring hook kit (to fiddle with sear spring, decocker spring, hammer retaining pin, and decocker/sear-cage pin retaining washer)

-Polymer pistol block

-Slave pin for decocker assembly (almost impossible to reassemble without this)

-No Third Hand this time, had to use both arms and both legs during the process.

-Those looking for pictures, can have a look at the youtube videos, it was more or less what I did, although it looks pretty simple in the videos, is more difficult in real life...or was it just me! I did not touch the trigger group..



http://www.youtube.com/watch?v=mSOY9OvLrBg


http://www.youtube.com/watch?v=IOsojk4fJss

RESULT
The trigger break was 4.5 lbs after the modification, reduced from 5 lbs prior. I expect this to go down to 4 lbs in time, as the weapon was NIB still. There was no creep after the change in hammer. Absolutely no creep. Competition level SA break, very smooth. I have two offers for the weapon now, one of the proposers have only heard about this over the phone!

And yes, some very very, very sore finger tips (and a couple of cuts as well), all taken care of by the satisfaction at the range!

Have now fired exactly 100 rounds in two sessions, chinese red box, barnaul, s&b 124 grains, pof2z (original or not, they worked). All through without any sort of malfunction.

TOTAL MODIFICATIONS ON PISTOL
-Competition hammer (looks exactly standard, but has a different hook profile, to give crisp, smooth and instant break. A matching disconnector was also installed.
-Reduced power springs: main spring for DA pull (13 lbs, also helps in racking slide!), firing pin spring to ensure reliable ignition with weaker main spring, and firing pin lifting block (fplb) spring to reduce creep in pre-travel, as well as trigger weight. Can almost not feel the fplb.
-Night Sights by Meprolight (good news is they were spot on in the first install, did not need to readjust at all by tapping them after shooting!)
-Cocobolo full checkered wood grips by CZ.

Fresh and clear pics later, for the time being, below should suffice (to some extent)..

CAUTION
-I did repeated function checks. One after reassembling the sear cage with slave pin. Then again after installing the sear cage in the frame. Both times with decocking lever installed. Repeatedly. Finally, function test after complete assembly of weapon. Slide racking, trigger reset, decocking function etc. I only loaded two rounds in first magazine at the range, just in case. They went fine. Next mag was five rounds.
-I do not intend to do any decocking type weapon again. Please do not venture in your weapons thinking that I may help you out if not manageable at your end!
-Again, not for the faint-hearted!

coolbox18
28-11-2011, 03:02 PM
The videos were a very good and helpful guide, would have taken at least another 2-3hrs without them. Total time to complete operation was about 3hrs. The decocker re-assembly was very tricky.

Asif Ali
28-11-2011, 04:06 PM
@Coolbox18
Can we change Decocker to Manual Safety also through modification?

R Shahreyar
28-11-2011, 06:41 PM
Whats the Price of CZ compact in karachi and its size as compared to Stoeger Cougar ?

Sami
28-11-2011, 11:28 PM
A.O.A, once again very nice job. C.Z looks as COOL as you are. If you were here, you might be facing a dilemma of confiscation rather than offers. Allah-Hafiz

AK47
29-11-2011, 08:54 AM
I agree with Sami Sb above, had I had a CZ-75D, this operation would have been insisted upon to be carried out by your good, competent self, at absolute gun-point, if necessary! Lol.

Humbly, you should gradually start contemplating moving Czech, I'm sure the maker requires such patiently competent staff.

Great job done. (Do I need to remind you of another "shoot-able"). Lol.


Regards.

Trigger_happy78
29-11-2011, 09:42 AM
Nice job bro, the CZ now looks way cooler now but you my friend are Sub-zero

coolbox18
04-12-2011, 12:45 PM
@Asif Ali bro
The amount of labour and parts involved will be so high that you are better off changing the weapon, as frame and sear cage have different designs, and holes/notches are in different positions etc.
@R Shahreyar bro
I think price is between 110k-125k, size is slightly smaller and thinner, but you have to see for yourself by holding them togehter.
@Sami bhai,
I am both lucky not being there so my weapons are safe, and unlucky also as I miss the company of Lahore, Sialkot and Pindi brothers..
@AK47 sb,
thank you for the praise, again. I am sure CZ would not mind having me here than there, as they would lose a 'good' gunsmith in Pakistan, and get a 'bad' one up there if I was to join them in Czech Republic...
I would however not mind 'exchanging' 'gifts' with brothers!
@Trigger happy bro,
I am not sure about 'sub-zero', but definitely was 'stone cold' when the parts popped open in this decocker model!


The trigger after 100rounds is now 3.75 Lbs..

coolbox18
04-12-2011, 12:46 PM
@Asif Ali bro
The amount of labour and parts involved will be so high that you are better off changing the weapon, as frame and sear cage have different designs, and holes/notches are in different positions etc.
@R Shahreyar bro
I think price is between 110k-125k, size is slightly smaller and thinner, but you have to see for yourself by holding them togehter.
@Sami bhai,
I am both lucky not being there so my weapons are safe, and unlucky also as I miss the company of Lahore, Sialkot and Pindi brothers..
@AK47 sb,
thank you for the praise, again. I am sure CZ would not mind having me here than there, as they would lose a 'good' gunsmith in Pakistan, and get a 'bad' one up there if I was to join them in Czech Republic...
I would however not mind 'exchanging' 'gifts' with brothers!
@Trigger happy bro,
I am not sure about 'sub-zero', but definitely was 'stone cold' when the parts popped open in this decocker model!


The trigger after 100rounds is now 3.75 Lbs..

Aquarius
04-12-2011, 05:38 PM
Beautiful work done there indeed.. totally missed this thread.

coolbox bro you are becoming the official gunsmith of CZ for PakGunners.. will certainly require your help if am stuck somewhere.

HussainAli
04-12-2011, 06:29 PM
Dear CoolBox Bro, Very nice work indeed a very nicely explained writeup !!!

Keep it up !!!!

Regards

coolbox18
04-12-2011, 11:26 PM
@Hussain Ali and Aquarius brothers, thank you.

@Aquarius bro, just sharing what I have learned, and I started learning at PG! Available whenever you need my services.