Question about ammo and experiences with VZ58

[StevenJ61]

Hey all just had a quick question. For my 7.62 by 39 rifles, I've pretty much only shoot Yugo M67 brass ammo with some Wolf and Winchester rounds. Recently I tried out some Russian Golden Bear ammo in my VZ2008 rifle. It fed and fired well but it seems as thought it's unlocking a hair early as forty percent of the time I see a bright instant flash coming from the chamber area. I inspected the chamber, I don't see any damage, locking lugs are fully engaging. I then ran some Yugo M67 through to make sure it wasn't due to changing my bolt carrier and sure enough the M67 shot the same way it did with my last bolt carrier with no giant instant flash from the chamber area. It may just be the Golden Bear is that much hotter than the M67 Yugo ammo. Anyone else shoot Bear ammo through their VZ2008?

[Brasky]

I have not used golden bear but I have used brown bear and silver bear and both seemed identical to Wolf and Tulammo.

Any reason you are using the more expensive golden bear?

[FallenEagle]

I've used Golden Tiger and the vz seems to like it rather well.

[MP2 Guy]

I've used Brown Bear, Silver Bear, Golden Bear, and Tula in my vz. 58V.  All fired well and, as normal for a vz. 58, got the barrel very hot.

[StevenJ61]

I wanted brass plated because of stories I heard of laqucered steel cases getting stuck in the chamber after extended shooting. Also it is still vastly cheaper than all brass cased ammo. Even holds true when compared price wise to Yugo m67. Plus I do not yet reload so brass plated is sufficient for me. With that said I have ran Wolf laqucered ammo befor with no issues but only firing off 20 tp 60 rounds of Wolf at a time. I have been thinking of getting a spare locking to see if it would keep it locked longer. Of course if I do that I then need to check headspacing etc. I may be making a mountain out of a mole hill. I just do not want the chamber rupturing on the rifle due to the bolt unlocking too early. That was my real concern and so far only Golden Bear has caused this chamber flash. Now I did swap the bolt carrier with one that is tabbed. I did fire it with m67 ammo in the same session and there was no chamber flash with that ammo.

[armoredman]

I have never had that issue with any ammo, factory or handloded, in my old vz-58.  Is that a home build, Century ,or CzechpointUSA rifle?

[StevenJ61]

Century 2008. I did swap the bolt carrier with one that is tabbed. I bought a surplus bolt with premade tab from CSA for it. I had someone weld it together for me. Like I wrote the Serbian ammo does not do it. The bolt closes all the way forward and the locking lugs engage fine. I checked it numerous times against the original carrier and I saw no change in lock up. It could be just me. It was an indoor range. Muuzzle flash is always far more noticeable on indoor ranges.

[RSR]

Yugo M67 is known to be "low flash" ammo.  I would assume it has flash retardants, but don't know for certain. 

Golden tiger definitely has flash retardants in powder. 

It is unclear if the Barnaul/Wolf mil-spec ammo (lacquered cases, sealed primers, etc) uses flash retardant in powder or not.  But one could safely assume that most if not all of the standard Barnaul Bear ammos use powders w/o flash retardant to maximize profit w/ their low price point ammo...

Barnaul, Tul, etc, Russian ammo is know for very inconsistent muzzle flash signatures as well if you look at any of the muzzle flash 7.62x39 vids where they show multiple rounds, or threads discussing the same.

EDIT: What causes the bolt to unlock is the piston striking the bolt carrier and moving it to the rear.  The bolt carrier has to move to unlock the locking block and accordingly release the bolt.  Best case to check if there's an issue with the locking block not engaging would be to put steel rod down bore and see if you can force it out of battery, but you might damage bolt or barrel...  Best advice I can give is to perhaps look into replacing both your recoil and striker springs with brand new -- VZ2008s' springs should be considered used and of unknown quantity.  The recoil spring is the primary recoil dampener, but the striker spring definitely assists as well.

Steel cases are less likely to swell than brass.  Get some brass cased ammo and see if those fired cases show any odd bulging, etc, that might support your unlocking early hypothesis.
My instinct is just different ammo, but perhaps not -- through night vision all semi-auto guns usually show flash at the ejection port -- haven't really studies chamber ejection for flash at dark as I rarely shoot at night except varmints.

[StevenJ61]

RSR, thanks for the thoughts and information about retardants in different ammunition. I had actually just bought a replacement dust cover with recoil and striker springs. I found the issue with it and it was the bolt carrier group.



See the area in red? I filed the insides of the lips that fit around the gas piston housing. Now the bolt carrier sits about 1/32nd of an inch further forward give or take  a few fractions. I noticed after further examination the old bolt carrier sat a little closer to the front trunnion/ gas piston housing. The original bolt carrier was about 3/32nd of an inch away from the face where as the replacement carrier was about 1/8th. Took me a while to notice but I just fired the rifle since the change, forty rounds of Golden Bear and forty of M67. With the Bear I still get an occasional chamber flash but it's tame, it's not blinding like it was a few days ago. No ruptured cases, the Yugo brass and the Golden Bear steel cases are fine.

[knoxy]

I've fired a couple hundred rounds of Golden Bear soft points through my vz2008 without a problem. Don't recall seeing a flash at the chamber, but sometimes get powder residue on my face shooting the dirty Russian stuff.

I did have a lacquer coated steel cartridge seize in my chamber once, after about 1000 rounds. Gave the chamber a good scrubbing with a 20gauge bore brush and it has been fine for the last 2000 rounds or so. Now I just give it a scrub once in a while, 500-1000 rnds.

I generally stick with Golden Tiger and haven't had any issues.

[RSR]

Changing bolt carriers can affect headspacing. 

This was intended to be rectified by changing locking blocks/pieces, not by filing on the carrier insofar as I'm aware.  The carrier itself shouldn't be bottoming out against rear sight block.

[StevenJ61]

RSR, I understand what you wrote but the carrier was not sitting as close to the rear sight block as the original. The Century receivers are slightly different spec from what I read than the original Czech receivers. Either way, filing it a hair which let the carrier sit further forward did increase the time it spent in lock up. The ammo I fired was Golden Bear Hollow Points not soft points. I think their Hollow Points are a little hotter. I tired to find the soft points but didn't see them for sale, however J&G sales had the Hollow point Golden Bears.