Replaced recoil springs. Cure for broken bolts?

[TJNewton]

It's been a while, but I've had two bolts in separate rifles have the narrower front lug sheared off.  The threads below go into detail:

https://czfirearms.us/index.php?topic=96542.0

https://czfirearms.us/index.php?topic=106694.0

I haven't shot them much since them, having soured a bit on VZ's.  It's a disappointment as I like these rifles and have spent a lot of time and effort with them.  I recently wondered if the recoil springs could be worn.  I replaced all three with NOS, which were about 2 1/2" longer than the old ones in the rifles.  For maintenance, I also replaced all striker and piston springs, although those looked much better and were negligibly shorter. 

I keep flip-flopping conceptually as to whether new, stiffer recoil springs would ease the abuse inflicted on the bolt lugs during firing, or exacerbate it.  I know with my handguns a weak recoil spring can cause a failure to feed due less return pressure, and I would think the same principle would carry over to the VZ, and in that frame of mind it would push the bolt harder into battery and exacerbate the abuse.  But on the other hand, a stiffer recoil spring with more resistance would theoretically lessen the travel of the bolt, providing a shorter and softer return.  Maybe someone can clarify which perspective is correct.

I hope this was the problem.  Eager to take the VZ's out again.  Time will tell.

[MeatAxe]

Looking back at your previous threads, I see you have a Century Vz2008…there have been A LOT of issues with those, so I wouldn’t let that sour you on the Vz58. Have you ever tried a CSA / D Techniks manufactured / assembled Vz58? They’re pretty much top of the heap in the Vz58 game.

[TJNewton]

I start the first thread by referring to another VZ owner who had the same lug shear off -- his rifle was a Czechpoint/CSA.  When researching I found a couple -- not many -- occurrences in Canada with non-Century rifles.  I don't think it's extremely common and probably due to metal fatigue on highly-used surplus parts and could happen with any build.  That it happened to me twice is par for the course of finding myself in one of the tails of the bell curve.  I'm familiar with Century's dubious reputation overall, but other than that I've had no problems with the VZ2008.  Several thousands of rounds through them.

What is your opinion on whether new stiffer recoil springs would ease or exacerbate the abuse on the bolt during cycling?

[TJNewton]

It seems that the sheared narrow lug may be more common.  This is a link to a supplier of surplus parts.  One the bolts pictured has that narrow lug sheared off.  I've bought a few parts from here and I'm sure the supplier wouldn't ship that out.

https://clearviewinvest.com/vz58-bolt-w-firing-pin-extractor-extractor-spring-extractor-stay/

[MeatAxe]

I start the first thread by referring to another VZ owner who had the same lug shear off -- his rifle was a Czechpoint/CSA.  When researching I found a couple -- not many -- occurrences in Canada with non-Century rifles.  I don't think it's extremely common and probably due to metal fatigue on highly-used surplus parts and could happen with any build.  That it happened to me twice is par for the course of finding myself in one of the tails of the bell curve.  I'm familiar with Century's dubious reputation overall, but other than that I've had no problems with the VZ2008.  Several thousands of rounds through them.

What is your opinion on whether new stiffer recoil springs would ease or exacerbate the abuse on the bolt during cycling?

In your case, sounds like replacing the recoil spring with a new, in-spec (stiffer) part, would be the right call, rather than using a worn out, soft spring where the bolt / carrier are going to be slammed around in the receiver with excessive force, which may result in your lugs getting sheared off. Of course, using new in-spec wear parts, such as the recoil springs is always going to be better than using old worn out parts…

What I’m intrigued with is the KNS prototype for an adjustable gas piston for the Vz58 — now that would be a great upgrade! I have some of their adjustable gas pistons for AKs and they work very well, especially since most AKs are badly overgassed.

As far as CSA vs. Century, IMO, buy once, cry once (and that Lothar Walther barrel is really accurate). As you say, in most cases, Century has a spotty reputation, while CSA has a pretty good rep and they seem to stand by their products. I’d rather spend my time shooting rather than fixing.

[TJNewton]

I start the first thread by referring to another VZ owner who had the same lug shear off -- his rifle was a Czechpoint/CSA.  When researching I found a couple -- not many -- occurrences in Canada with non-Century rifles.  I don't think it's extremely common and probably due to metal fatigue on highly-used surplus parts and could happen with any build.  That it happened to me twice is par for the course of finding myself in one of the tails of the bell curve.  I'm familiar with Century's dubious reputation overall, but other than that I've had no problems with the VZ2008.  Several thousands of rounds through them.

What is your opinion on whether new stiffer recoil springs would ease or exacerbate the abuse on the bolt during cycling?

In your case, sounds like replacing the recoil spring with a new, in-spec (stiffer) part, would be the right call, rather than using a worn out, soft spring where the bolt / carrier are going to be slammed around in the receiver with excessive force, which may result in your lugs getting sheared off. Of course, using new in-spec wear parts, such as the recoil springs is always going to be better than using old worn out parts…

What I’m intrigued with is the KNS prototype for an adjustable gas piston for the Vz58 — now that would be a great upgrade! I have some of their adjustable gas pistons for AKs and they work very well, especially since most AKs are badly overgassed.

As far as CSA vs. Century, IMO, buy once, cry once (and that Lothar Walther barrel is really accurate). As you say, in most cases, Century has a spotty reputation, while CSA has a pretty good rep and they seem to stand by their products. I’d rather spend my time shooting rather than fixing.

I think you're right about new springs.  I took the rifle out today and put 140 rounds through it.  It seems fine.

VZ2008's seem to be Century's unicorn.  Once the carrier is tabbed, there are few reports of problems.  Sure, some are uglier than others, and some need some parts changed out, but overall they seem to be robust.  I have one with 5,000 rounds through its Green Mountain (reputedly) non-chrome lined barrel and it's still shiny with sharp lands and accuracy is a good as day one.  With irons I'm getting 2-3" groups at 50 yards and 4-8" at 100, and I have fairly significant astigmatism.  I've added receiver peep sights to them and that really cleans up the sight picture and yields even better groups.  Probably greater improvement with a scope.

I'm starting to get sweet on these again.  I don't doubt a Czechpoint is an excellent build, but I got the VZ2008's for $400 a piece way back when, and Czechpoints and even original VZ58's are susceptible to the narrow lug problem.  That may be a design deficit, requiring periodic freshening up of springs.  I also replaced the surplus Czech piston with a flat face with the original Century dished piston.  That, and the new springs, seemed to make for a softer recoil, however subjective that observation may be.

Thanks for your insights.

[RSR]

I'm starting to get sweet on these again.  I don't doubt a Czechpoint is an excellent build, but I got the VZ2008's for $400 a piece way back when, and Czechpoints and even original VZ58's are susceptible to the narrow lug problem.  That may be a design deficit, requiring periodic freshening up of springs.  I also replaced the surplus Czech piston with a flat face with the original Century dished piston.  That, and the new springs, seemed to make for a softer recoil, however subjective that observation may be.

Memory serves -- they were $400 w/ 5 mags, a bayonet, a mag pouch, and a cleaning kit...   So less than $300 for the firearm itself.