Pics of SBR vz58

[rocinante]

sandstone those under folders look sweet. Did you make your own adapters?

[Sean K.]

Back in the day when we were trying to get the XM-177E2 to run we found that 10" barrels were nice, but, the function was unreliable...unless suppressed.  The muzzle flash with the ammunition of the day was like a flame thrower.  Eventually it was learned that 11.5" barrels would produce more reliability.  I guess you could experiment with different powders and bullet weights in a VZ58 SBR.  It would stand to reason that a heavier bullet weight like a 135gr and a faster powder like N120 or IMR 4227, might raise gas propagation and pressure to a higher level per unit time.  My AR SBR with the 11.5"bbl gets iffy without the Suppressor if I use 55gr, and Varget or IMR-4064.  It straightens right out when I use IMR-4198 (faster burn rate). Just a thought.

Recently, I started experimenting with my VZ58 and 527 in 7.62x39 with various .308 bullets and the accuracy has been good.  The coolest revelation has been with 110gr HPs. Results will be posted when I get done with the tests.

I have a couple of SBR (10.5") LWRC ARs a pair of SBR XCRs (9.5" and 10.5") and now the VZ.   The LWRCs (one is a 6.8, one is 5.56) took 2 trips back to the factory to get running 100% (I don't own any suppressors yet) with any ammo.   The XCRs were an absolute nightmare due mostly to piss poor quality control.   I finally got them running myself after giving up on Robinson Armament.....they now will eat anything I put in them.......I run alot of cheap, steel cased ammo like Wolf or Brown Bear in the XCRs since the extractor IMO, is heavy enough to not see any appreciable wear like an AR extractor.  The LWRC in 5.56 will eat Wolf like candy.....but I prefer not to feed it that ammo.

Basically, I've been able to diagnose the problems and get them fixed and have learned an awful lot about over/under gassing shorter gas systems (though to be fair....all of mine have been piston systems....trying to get a DI AR to run with a 10.5" or shorter bbl is quite a bit more difficult).  Now that I've got those rifles squared away....I'm hoping to be able to work on the VZ and get it working as it should.  I would actually be doing the work on it myself.....but I'm unfamiliar with what it takes to remove the gas block/lower handguard ring.  I have a 20 ton press and bearing puller plates.....but I'm not sure I can get the gas block off without damaging something.  I'd LOVE to learn how simply b/c I have an idea to *possibly* increase the dwell time on the shorter VZs to strengthen the ejection pattern....but I can't really try it out unless I figure out how to press the gas block off.   When I get the rifle back from the smith....I'll probably shoot it and if it's still not running....I'll be trying my hand at it.

Anyway, if anyone's interested in a decent article on how under/over gassing affects rifle performance.....this is a good article (though it's primarily geared toward DI ARs).

http://ar15barrels.com/prod/operation.shtml

[Sean K.]

Sean did you modify/ weld the stock folder or is that something commercial? I have aces on both my saiga shotgun and rifle.

I welded the stock folder myself after plasma cutting the cold rolled 1/4" plate to the shape you see.....I plan to do the same on my SBR....but I want to add a bolt on cheek 'buffer' out of UHMWPE (probably) about 3/4-1" in diameter to the I beam at the top....but one that doesn't raise your cheek weld more than a small amount (like 1/4" at most) as the folder's angle is perfect for cheek weld for me....it's just pretty sharp in terms of recoil and the squared edges are less ergonomic than I'd like.

Sean

[rocinante]

Sean if you ever decide to mod another side folder do up one for me. I am serious, that just makes the folder seriously good looking.

[Sean K.]

Sean if you ever decide to mod another side folder do up one for me. I am serious, that just makes the folder seriously good looking.

I think I'm going to lengthen the SBR one by 1/2"....would you want the LOP lengthened?  My nose hits the sling loop at the stock length.  I added an XCR solid rubber butt-pad to the 16" CAI  rifle to get my nose away from it.  I cut the loop off the SBR and made a much smaller one out of 3/16" cold rolled so my nose doesn't hit it so I could probably get away with the stock length. I was just thinking of doing the longer LOP for the heck of it.

Sean

[sandstorm]

sandstone those under folders look sweet. Did you make your own adapters?

i bot it that way but im sure if you have a machine shop , you could fabricate one too.

[7.62]

I had been thinking about SBRing a Draco for a while, then thought about just doing it to the VZ58.  I don't have other AK rifles, so I'd have to buy mags for it, ect.  However I bet that the cost would be cheaper to SBR the Draco vs the VZ58, and I'd have another rifle.  That's always a nice advantage, right!

How much does it usually cost to have someone do the work for a SBR VZ?  The Dracos sell for about $350 and the work required to make it an SBR is pretty simple (just modify the rear part of the trunion to accept a stock).

The tax is the same so it's a moot point.

[Sean K.]

I only paid $150 for the shortening and port opening.....but then again, mine doesn't work....so take it FWIW.   I paid about $100 to have it engraved.  The stamp was $200 obviously.  I doubt it's any cheaper to do the Draco than the VZ....though VZ bbls are notoriously hard to get out of the receiver (in my case it was impossible, so the smith had to put the WHOLE rifle in special lathe to make sure the threads were concentric to the bore.....and come to find out D-Technik had drilled the bbl out of concentric by 20 thou....making it that much more difficult).

HTH,
Sean

[7.62]

"then again, mine doesn't work"  LOL.  Sorry man but I had to laugh when I saw that.

All joking aside that isn't bad price wise.  I'd prolly send it off to In Range in TN to have them do the work as they're experienced with making VZ58 SBRs.  I know my smith here is super expensive for the slightest amount of work; he still is constantly busy.  Did you wait until you got the form back before you sent it to your smith for work?

[Stevo]

My 11.75" CSA VZ in a few different configurations:

[Sean K.]

"then again, mine doesn't work"  LOL.  Sorry man but I had to laugh when I saw that.

All joking aside that isn't bad price wise.  I'd prolly send it off to In Range in TN to have them do the work as they're experienced with making VZ58 SBRs.  I know my smith here is super expensive for the slightest amount of work; he still is constantly busy.  Did you wait until you got the form back before you sent it to your smith for work?

I'd recommend Troy at In Range as well....though he told me that he wasn't sure if he'd do more VZs....apparently, they are a PITA to work on.  At the time, he was going to be busy (June of 2010) for 6 months building AKs....so I went local.  Little did I know I wouldn't get my rifle back until December anyway....and it doesn't run.  

I did a form 4.....meaning the smith essentially built the SBR, and filed the form 4 with ATF when I dropped the rifle off in early July.  In early September it was approved and back with the smith.  I'm pretty sure if you're a class III builder/dealer, you can mfg the gun as soon as you notify ATF that you're going to build one....you just can't transfer it to the owner until the form 4 is approved and sent back.

HTH,
Sean

[Stevo]

Sean,
In your thread on CGN I mentioned I hadn't shot my SBR at temps above -20 C yet. I had it out last week with the temp a few degrees above freezing. The ejection was still not as vertical as with my rifles, but it did seem more vigorous. Still no FTF/FTE.

Steve

[Sean K.]

Sean,
In your thread on CGN I mentioned I hadn't shot my SBR at temps above -20 C yet. I had it out last week with the temp a few degrees above freezing. The ejection was still not as vertical as with my rifles, but it did seem more vigorous. Still no FTF/FTE.

Steve

Thanks for the info Steve.....man, I wish I could get mine running.  Love this gun and this platform but this SBR in particular is making me wish I'd left it alone.  It was 100% before I messed with it.

Sean

[Stevo]

Have you examined the entire rifle carefully, not just the gas system? Is it possible your smith could have damaged the receiver or spring guides or Do you have a spare recoil spring? You could try snipping a coil or two off at a time (I'm really grasping with that suggestion).

What about a Noveske-style muzzle device? Dlask ripped off the KX3 with VZ threading and it should fool the gas system into thinking the barrel is longer.

[armoredman]

A gas retarding muzzle device, that might do the trick!