Replacing broken VZ58 Bolt

[vz58b]

Hi there, Im new to the forum and have a few questions about the vz58 bolt. Sorry if this has been asked before.

The make of the rifle is CSA(Czech small arms) and the bolt has a minor(?) break at the rear of the bolt, missing a piece of the bolt mass, just above the left side pivot point of the locker. The firing pin was also broken. Now I'm unsure what the cause of this is, but find it very coinciding of a rare occurrence just recently experienced. While at the range using czech milsurp ammo I had a nasty stuck case(Actually 3) requiring a rod to remove. The extractor ripped off the corresponding piece of casing, and am wondering if an out of battery fire occurred.

 I am lucky enough to have a milsurp armorers kit with spare bolts. Can I drop in a new bolt like I can an AR? I want to make sure I know what I'm doing, if that require also changing the locker, carrier etc. I do not have a set of headspace gauges but will be ordering them.

Any of you familiar with doing something like this, and any experience/discretion would be greatly appreciated.

Thanks

[TJNewton]

I'm sure that some with more experience will speak up, but if you have the gauges on the way, wait until they arrive.  I don't think you can drop in another bolt and fire safely.

Regarding the gauges, there are two kinds:  SAAMI and CIP.  Each has slightly different dimensions.  SAAMI is western firearms and ammo, and CIP is Soviet Bloc.  I believe that the Chinese used even different dimensions.  From what I've read here, the VZ58 variants are somewhat forgiving, enabling the VZ2008, with a SAAMI cut chamber, to safely fire CIP ammo.  I don't know what dimensions the chamber of your CSA rifle are.  Apparently, due to the number of production years and factories, specs vary widely even between original Czechoslovakian VZ58 rifles.  And then you add in aftermarket variants and things get even more complicated.

A few months ago there were quite a few threads on this very subject.  I vaguely remember some members encountering ambiguities when using gauges on these rifles.  The best thing is to go over those threads, then post follow up questions.  This site's search bar doesn't work very well.  Go to google and type in (without the quotation marks) "site:www.czfirearms.us" followed by key words.

[vz58b]

Thanks, Ive been reading other posts on here regarding the headspace and how to go/no-go it. Although its is a little confusing on what is being called acceptable. Also I was not aware of the different dimensions of CIP, I'm not sure if my barrel is surplus or aftermarket.

[CitizenPete]

Thanks, Ive been reading other posts on here regarding the headspace and how to go/no-go it. Although its is a little confusing on what is being called acceptable. Also I was not aware of the different dimensions of CIP, I'm not sure if my barrel is surplus or aftermarket.

If your gun is older, the barrel is less than 16" and/or the muzzle device is permanently pinned on (USA), and it is chrome lined it is probably original military surplus.

[JohnEd]

That barrel pin can easily be driven out.  The barrel can be pressed further in or pulled out as the case may be.  On an OEM this operation will require a hydraulic press and jigs to hold the receiver vertical and also fit into the receiver to impinge against the barrel end.  Use that penny to protect the barrel.  Pressing the barrel IN will be simpler:  Drive the barrel into the receiver using a very heavy brass hammer.

I drove my barrels into the receiver using the brass hammer and had the "Go" gauge chambered to stop the forward drift.  I could hear and see the bolt/receiver go to zero clearance where I stopped.  So the GO fits and the proof is you install the NO-GO and the bolt carrier stands clear of the front sight block when the bolt is in battery.  Actually, in that case, the bolt is being held OUT OF BATTERY.

My CSA closed on the NO-GO gauge.  Super bad news for m,e but seeing as I had run a thousand rounds thru the gun I ignored it.  I replaced that barrel and built two more guns and they are spot on and work really well.  Seems the 58 is forgiving as many have said their carrier/bolt has no gap when the NO-GO is used.

ALERT!!!!!  Once you get that barrel positioned where you want it you must add that pin back injto the picture.  problem is you cannot use the same hole as the hole will no longer be aligned.  you need to drill another hole that goes thru the receiver and the barrel and that hole has to be carefully reamed to a circle with a reamer.  Only CARBIDE drill bits will work reliably as the receiver is as hard as a file and will shatter HSS and the other super hard steel.  COBALT is hard and tough and worth the $4.50.  That reamer needs to be hard also.

If you have to move the barrel to regain proper head-space you might consider replacing the barrel with a true 308 bore.  The chrome is 312 or 313 to retard barrel overheating during full auto firing.  We can't do the so the more accurate barrel is a plus instead of a guaranteed casualty on the battle field.  Then you can use the original holes to get your new pin in the barrel.

Another thing you might consider is when you get your gauges and you determine there is a head space problem contact Dan Brown and see if he has bolts that are slightly over/under size.  Your barrel should be even with the back edge of the receiver and mine was but the HS was huge and all later builds were perfect.

Good luck and happy new year.

John