Semi Auto Vector Arms' Uzi

[brown8775]

I have a Vector Arms Semi Auto Model A Uzi Carbine. Today upon reassembling it, I noticed that the edge of the little, spring tensioned, pivoting piece at the back of the bolt, which looks as though it is meant to rest on the flat ground-edge of the disc that surrounds the base of the firing pin, looks either prematurely worn or perhaps chipped or smashed.
Upon reading the manual, I saw no mention that you are supposed to rock the little part on the rear of the bolt so that it rests on that disc's flat edge when putting together the firing pin assembly and the bolt before inserting them into the receiver.
I noticed that it looks like you are supposed to set it this way, or why would they have ground that disc at the base of the firing pin?! I noticed that if you don't manually rock that spring-loaded piece forward, that the firing pin base piece rests against its edge, instead of the way it looks that it should be. If you leave it this way, it seems that the base of the firing pin gets forced against that little rocking piece, which I believe happened in my case, chipping/crushing the little rocking piece a little bit.
Am I correct? If so, then why is there no mention of this in the manual?! How important is this? Does anyone know anything about what I'm talking about? I'd really like a "Learned/Professional" opinion if such an one exists out there.
Thank you,
M

 

[RoverDave]

You are correct about the way the piece on the bolt, which is called the blocking latch, interacts with the cut out in the base of the firing pin. When I assemble one, I normally depress the blocking latch so the firing pin rests firmly on the back of the bolt before assembly. However, if you don't do that, it normally gets depressed anyway as the bolt moves all the way forward. That's how it's designed to work. When the bolt moves all the way forward against the barrel/barrel trunnion, the ejector pushes the blocking latch up and out of the way. It's hard to say without seeing pictures of this, but it seems more likely that there's something wrong with the gun rather than a problem with the way you're assembling it. The original Model B is when the blocking latch was added. It also had a different style ejector so it would trip the latch better. Maybe it's the ejector that's beating up the blocking latch when you shoot it rather than something you're doing when you assemble. How much have you shot it?

By the way, the vector model numbers (like Model A) is no real indication of which parts are used in the gun. Vector uses whatever parts they can get and it does not correlate to the original Model A/Model B designation.

 

[brown8775]

Thanks RoverDave,
I've shot only approximately 700-800 rounds so far from my Uzi. From the looks of the damage/wear that I've noticed, the best guess I can come up with from what you're saying is that the ejector may be misaligned such that it's not interacting with the blocking latch the way that it should be.
As for Model A vs. Model B parts, from what I've learned on Uzi Talk's comparison page, I thought my gun was all Model A parts, though it does have some peculiarities that I'm pleasantly surprised with, such as a Hebrew lower and a full-auto top cover. I'll have to go review that page again to see what I missed...
It's still under warranty, as I've had it for a mere 2 months. Now I'm wondering how I'll be able to check the interactions of these two parts, as they are unobservable when together and working...
Thank you again for the reply!

 

[brown8775]

Alright, I just looked at the comparison page again and I see what you're talking about... I wonder now also if I have an "A" style ejector with the "B" style bolt and if that could have something to do with it...
It really does look as though the blocking latch is not being pivoted by the ejector correctly, judging by the damage/wear.
I'm also wondering if it even matters, as long as my gun is firing well, which it is...
Hmmm...

 

[brown8775]

Hey RoverDave,
I just checked and I do have a Model B ejector as well...

 

[RoverDave]

Post some pictures of the damage to the blocking latch, the base of the firing pin that engages with the blocking latch, and the extractor. We might be able to spot something if we can look at pictures.

 

[HR2448?]

Dave , I looked at an earlier post about old style sears and came across your thread on it. It appears I have an old style sear with a model B bolt in a vector arms i just bought. It has hebrew markings and all three selector signs, does have the blocking bar for selector.serial number has 6 numbers,no markings on bolt or anything else. Any help?

 

[RoverDave]

The style of sear or disconnector should not have any impact on the functionality of the blocking latch.

 

[brown8775]

I called Vector Arms

Hello Dave,
I called Vector Arms and spoke to someone in the shop. I explained what was going on and he spoke with one of their gun smiths, who said they have run into the issue I'm having before. He said that the blocking latch is likely out of alignment. To avoid having to send the bolt to them, I asked if it would void the warranty if I were to fix it myself. They conceded and are sending a new blocking latch out to me. When I receive it in the mail, I am to call them and their smith is going to tell me over the phone how to ensure the new one is aligned.
I'm pretty happy with their customer service!
That said, he said if I were to leave it be that it would continue to work for a while, but that eventually I would begin to experience random 3 round bursts... to which I thought to myself: "Cool!" If not for likely warranty issues, I'd probably leave it as it is for the hope of those fun malfunctions!

 

[brown8775]

That said (see below), here are some photos in the hopes it may help others with diagnosis of this issue, since it sounds to be a relatively common issue.

 

[brown8775]

One more photo

Hello Dave, here is another, better photo of the latch... for some reason it wouldn't upload with the other 3...

 

[RoverDave]

Thanks for the photos. it looks like the blocking latch isn't being lifted high enough and the bottom edge of it (top side in the photo since the bolt is upside down) is hitting the base of the firing pin. I'll be interested to hear what they tell you to do to align the blocking latch. I'm not aware of any adjustment you can make to align it.

And by the way, even if it's due to a malfunction, three round bursts would be an unregistered machine gun. Not something you want!

 

[brown8775]

Damaged!

So... a little over a week from when I had posted the photos of the premature/odd wear that I noticed on the blocking latch, I went to the range. My first clip of the day, being a 20 round clip loaded with all factory rounds; i.e., not reloads. The first 16 rounds fired off normally... Round 17, however, was a different story.
I pulled the trigger. There was less recoil than normal followed by a large cloud of smoke wafting from my Uzi.
I removed the top cover and pulled out the bolt. The bolt was bent/deformed at the lower right of the bolt's face. The rail of the bolt near the front was also bent nastily. There was approximately 0.5 cm or so of the bullet's brass case jammed in the chamber end of the barrel. The barrel was otherwise clear; i.e., the bullet did shoot.
I left the gun as it was and, tears of sadness streaming from mine eyes, I sent it back to Vector Arms who are at present unsure if this was due to fault of the gun or the round.
Any educated opinions out there? I think it was an issue with the gun, especially as the round in question was not cheap/shitty ammunition. I'm no gun smith by any means though.

 

[badboy0757]

Sounds like the cartridge was fired out of battery. The blocking latch is supposed to prevent this but as yours is malfunctioning it may have actually caused it. You're lucky that the detonating cartridge was contained by the uzis telescoping bolt. This is a good example of why not to fire a malfunctioning weapon.

 

[Glockdude1]

Remove the blocking latch and see if the problem goes away.

:surfing

 

[Tom5390]

The way I see the gun was defective from day one. You contacted them and tried to fix it with their help and the gun was then extensively damaged by an OOB. Luckily no one was hurt. They owe you a new gun. Tell them they can part this one out. It was not the ammo by the sounds of it, so don't let them tell you that. Tell them you want a new gun. Preferably one that was test fired.

 

[brown8775]

Sounds like the cartridge was fired out of battery. The blocking latch is supposed to prevent this but as yours is malfunctioning it may have actually caused it. You're lucky that the detonating cartridge was contained by the uzis telescoping bolt. This is a good example of why not to fire a malfunctioning weapon.

This is what I thought! It makes logical sense when one considers the purpose of the blocking latch and the fact that I'd noticed that abnormal wear a week before. Note that I never had a malfunction before this; I merely saw a little abnormal wear on the blocking latch, as I attempted to photograph and post above...
When I brought this to Vector Arms' attention, they insisted that this could not be a result of the blocking latch. They insist that if the blocking latch fails you end up with 3 round bursts, period.
That said, I am no expert or gun smith. So... I'm curious as to what they'll say.

 

[bubbaguns]

That little piece of metal you guys are calling a blocking latch, I had a uzi years ago. I don't remember this peice in mine. I can't remember if it was an model A or B.
If it was added, why?

edited: I read in the reference section what it was for, but I don't understand the need for the extra safety. Was there an issue with the Model A firing out of battery?

 

[badboy0757]

There was a minor issue with OOB firing in the model As but only with extremely dirty weapons and even then it was a very rare occurance. I think the blocking latch was more a product of liability lawyers than any real world problem.

I fail to see how a malfunctioning blocking latch could cause perfect 3 round bursts? Its much more likely to cause misfires or fail to fires.

I imagine that it would function alright if the blocking latch was removed altogether. Its really just an add on safety feature that prevents the firing pin from contacting the primer until the bolt is fully closed.

Another thing to check on is the sear lug and the striker leg that contacts it. If these don't mesh properly the striker could conceivably slip off the sear and fire the cartridge.

 

[brown8775]

Reightous

Well, I heard from Vector Arms yesterday and I am very pleased with them thus far.
First, they began inspecting my gun immediately upon receiving it in the mail; i.e., on the same day they received it.
Second, upon seeing the gun, they remained honest and are not trying to pass the blame; they are going to go through the entire gun and recondition and/or replace everything damaged free of charge to me.
Vector agrees that it appears to have fired out of battery, and are going to let me know what they think may have caused it to do so, provided they can figure it out.
Finally, it sounds like they will have the gun back to me in a week or two, so we'll see how that pans out.