Stovepipe malfunctions

[Delasangre]

Hey everyone. I put together an UZI semi auto with a Mckay receiver and semi bolt kit, I have a BWE parts tri-lug barrel and the rest is an Israeli parts kit.

Since I built it I have run maybe 1000 rounds and some days it runs 100% and others I have multiple stovepipes per mag. I checked the top cover clearance and I think its good, it doesn't work more or less reliably with the suppressor, it doesn't make a difference if I use 124gr nato spec ammo or cheaper weak stuff. I tried a different recoil spring also to no effect.

At this point I have 2 ideas I want to try, either cut some off the buffer to get the bolt to move further back and give the empty more time to eject or cut some loops off the recoil spring. Any help would be really appreciated.

 

[BWE Firearms]

You have to run hot ammo in an Uzi. They will jam with week ammo.

 

[Mackjack]

Does the extractor hold a cartridge properly

 

[Delasangre]

You have to run hot ammo in an Uzi. They will jam with week ammo.

I am running some very warm 124gr NATO spec 9mm and it doesn't run any better than wolf steel or blazer brass.

 

[Delasangre]

Does the extractor hold a cartridge properly

Yes, no problems there

 

[Delasangre]

Is UZItalk dead?

I am using the correct recoil spring
My extractor has good pressure on it and is clean
Topcover gap is perfect
Using hot ammo
Ejector is tight
No interference with mags

What am I doing wrong, ejection with +p powered ammo is landing 3-4 feet to my right. It stovepipes often and is better with gobs of rem-oil. I am inclined to try grease to keep lube in there longer but I'd like the gun to run better closer to the dry side.

 

[Mackjack]

How's the chamber? Smooth and clean?

 

[BWE Firearms]

Use hot ammo not warm ammo.

 

[Delasangre]

Use hot ammo not warm ammo.

How hot is hot and how do I get it running with normal ammo? For example is seems to be ok with some 158gr subsonic roundnose ammo I tried a while back

 

[Mackjack]

My century uc9 runs with any ammo. I really only shoot 115 grain bargain bin ammo actually and it runs just fine.

Perhaps hot ammo can just cover up some issues.

 

[Delasangre]

My century uc9 runs with any ammo. I really only shoot 115 grain bargain bin ammo actually and it runs just fine.

Perhaps hot ammo can just cover up some issues.

Exactly, it shouldn't need special ammo to make it run. My friends Uzi runs fine with anything too so makes me think I have a problem. But what is it?

 

[Mackjack]

Exactly, it shouldn't need special ammo to make it run. My friends Uzi runs fine with anything too so makes me think I have a problem. But what is it?

Post pics or videos.

That will bring intrest to the thread and get ppl to reply more

 

[Delasangre]

Post pics or videos.

That will bring intrest to the thread and get ppl to reply more

What am I supposed to post a picture of?

 

[Mackjack]

What am I supposed to post a picture of?

Anything helpful to diagnose. Someone Might catch something your Not seeing in a picture of the internals or something. An out of spec ejector.... Odd rub marks. Not sure. But it's extremely difficult to diagnose problems via just text alone

 

[Delasangre]

Anything helpful to diagnose. Someone Might catch something your Not seeing in a picture of the internals or something. An out of spec ejector.... Odd rub marks. Not sure. But it's extremely difficult to diagnose problems via just text alone

Fair enough. I'll take some after work. I'll also take video next time I shoot it to show it malfunctioning.

 

[velocityvette]

Might try drilling out your buffer so that the recoil spring sits in its cup in the rear of your McKay receiver. Easy cheesy to do, may try that.

 

[Delasangre]

Might try drilling out your buffer so that the recoil spring sits in its cup in the rear of your McKay receiver. Easy cheesy to do, may try that.

Thanks I was kinda wondering about that. Worth a shot

 

[velocityvette]

Thanks I was kinda wondering about that. Worth a shot

I wish i had some before and after spring weight measurements for ya but dont. It deff takes the preload out of the spring though.

 

[rentprop1]

What am I supposed to post a picture of?

I know it sounds crazy but have a friend hold your cell phone on video right near the ejection Port as your firing and then put it in slow motion it's easy to spot malfunctions when you can slow the video down and watch it we do it all the time with customer guns