Cz 52 loose breech

[Dr_Sick_MMA]

https://m.youtube.com/watch?v=FQB0MVGBGko

After watching this vid I went and checked all my cz's. At least half of them have at least a little play in the breech lock. Anyone else experience this?  The 52 had about as much as the one demonstrated in the video above.

[jerryberry]

No, mine is tight, no play. I do wonder how this effects safety, in regards to the barrel cracking at the breech. Thanks for finding this, I had never heard of it before.

[teckno]

I would like to discuss this topic further as there is not a lot of info concerning this issue.

I do not believe that any of the CZ52's have zero breach movement or play between the breach face and the barrel when locked.

In my opinion the best way to verify the play in the breach is to remove the recoil spring from the barrel and install the barrel Assembly into the slide.

Now while holding the roller cam back towards the chamber with your finger to "lock" the barrel to the slide you can try to move the barrel assy fore and aft to see how much movement there is and what parts are allowing the play.

I have measured my CZ52 with both the original barrel assy and a new unfired barrel assy.
Original barrel assy had .48mm play.
New barrel assy had .37mm play.

Rollers on both old and new were within within one thousand of an inch of each other.

What I found was most of the play was caused by looseness between the cut in the barrel that the roller sits in when fully locked and the groove in the center of the roller.
Installing new rollers would not help this situation unless they were custom ground where the center of the roller would be larger compensating for the barrel wear.

When you think about it, only the small area at the center of the roller is contacting the barrel channel is keeping the breach locked.

Let me know what you think.




 
   

[rdcinhou]

I just checked my CZ52.  There is absolutely no play in the breech.

I don't know the prior history of my CZ52, but it looks like one roller is older than the other as they have slightly different internal IDs and show different (i.e. not uniform) wear.

[teckno]

I just checked my CZ52.  There is absolutely no play in the breech.

I don't know the prior history of my CZ52, but it looks like one roller is older than the other as they have slightly different internal IDs and show different (i.e. not uniform) wear.

Did you remove the recoil spring and check for play?

[rdcinhou]

I just checked my CZ52.  There is absolutely no play in the breech.

I don't know the prior history of my CZ52, but it looks like one roller is older than the other as they have slightly different internal IDs and show different (i.e. not uniform) wear.

Did you remove the recoil spring and check for play?

Yes...followed your suggested technique of removing the recoil spring, reinstalling the barrel and roller block assembly.  When holding the block in place (rollers locked) there is no axial movement in the barrel. There is a very slight radial movement off the axis at the barrel exit, but not enough to measure the gap with the tools that I have. Definitely does not show any movement at the breech.

[ZedHeadHunter]

I just bought a CZ 52 for really good price. The surface finish had some rust on it and the grips were spray painted. A little bit of elbow grease got it looking pretty good today.

I started diving through the old posts and discovered this one about loose breech. When I measure mine it is around 0.35 - 0.40 mm, or roughly 0.015 in.

I watched the parts in the AGI Gunsmithing video regarding the loose breech. He never said how much is too much but he made it sound like any is too much. He went on to say that the way to correct this is to TIG weld material on the top rear of the barrel to lengthen the barrel slightly and then grind off material to make it fit. He made a very strong point that you don't want to overheat the barrel at all, as in weld, cool, weld, cool, until enough is built up.

It's hard to believe that a military firearm would require such strict fitting. I can't see a military armor painstakingly building up material and grinding it back off again on barrels for these. But there are several here that have posted no movement whatsoever, followed by other people saying that on a new barrel they are getting about as much movement as I'm am.

Can anyone report any issues or broken parts relating to loose breech?