Gunsmithing CZ 527 bolt

[Muriner]

I just got a brand new CZ 527 varmint mtr in 223 and while cleaning it for the first time I have found that the bolt has what I would describe as "parts of metal missing" (picture attached). Poor machining? They ran out of metal making all these guns during the crazy demand ? My other 527s don't have anything like that, their bolts are perfectly cylindrical there. I'm no gunsmith, but this seems to be more of a cosmetic issue than anything else since this is going to be behind the locking lugs. And I suppose there shouldn't be any related accuracy issues. But I figured I'd ask the experts here first before shooting it (or contacting CZ). It's annoying to see on a brand new rifle, though.

 

[Shootin Stuff]

Surely someone else with a .223 CZ 527 will chime in for comparison, but it looks like tooling marks to me (IE either intentional clearance or a machining fuckup)

Is there anything in your action near that location to indicate whether or not it might be a clearance cut?

I would hit up CZ for clarification and shoot it as is until you hear back from them. I wouldn’t be worried about a structural failure of the bolt though.

 

[Muriner]

Thanks! From what I can't tell there are no areas when it will help clearance, so I'll go with the machining fuckup theory

 

[mcfred]

I'm no "expert," but it looks like it's just a machine mark from chamfering the corner of the lucking lug:

The tool depth was just a little deeper than it should have been (tool path highlighted in red). It's what you get for Eastern European manufacturing. Should not affect function.

You can send it back to CZ, I'd be interested in hearing what they think about it, being that it's cosmetic more than anything.

 

[Shootin Stuff]

^^^^ That’s exactly what I was thinking.

If you do want it made right, they might try and talk their way out of a replacement because it’s an internal mechanism, but really what’s the difference between that, a gouged stock, scratched bluing, or a cracked Buttpad?

 

[Muriner]

Makes perfect sense, @mcfred !

I'll shoot CZ an e-mail to see what they say.

I should note that otherwise it's a very nice looking rifle. I will know soon how well it shoots.

 

[Muriner]

Update.

CZ got back to me very quickly saying that the newer models ('20, I assume, as my '19 rifles were perfect) can have these cuts from the milling process, but "you won't see it from the outside and it doesn't affect the performance or safety".

As my FFL put it: "you have to compete with the Chinese somehow". Still I'm disappointed to see CZ lowering its standards.

 

[mcfred]

Well, roll the claw extractor over and install the bolt and they're right, you won't even see it. Go shoot it and have fun.

If you're really bent out of shape over it then you can contact a 'smith that will stone it out, beadblast it and cerakote it and you won't be able to see it anymore even if you were looking for it.

 

[Muriner]

I'll just let it be, these cuts actually doesn't bother me much. It's true that it's not even visible from the outside.

 

[FCSA-UK]

I've noticed this also, most CZ527's with serial numbers starting with D26.... and just picked up what might be the last F prefix serial number here in the UK in .17 Hornet and that still has the issue, however its very slight and most people who were unaware of this would probably never notice.


I got a message from the factory last year, they openly admitted that a new CNC machine wasn’t setup quite right, but were clear that its a cosmetic issue and nothing more.

See pics, bolt from an D prefix serial number rifle (on the bubble wrap), and F prefix on the wooden table:

 

[carbonbased]

View attachment 7653358

View attachment 7653362

I have a CZ 527 in 17 Hornet and ita bolt has the exact same marks. Huh. Interesting.

Thanks for the pics. I was wondering what was up with that.

 

[charlies]