Completely new to the world of UZI full auto and am lost on a problem. I have a full sized Model A smg (Group Industries) set up as 9mm and having feeding issues. The bolt runs freely with the clip and recoil spring removed and appears to have the appropriate clearance from the top cover. The problem seems to be getting the first round to fire. Once running it seems to cycle just fine. When the clip is in and full (32 rounds) the bolt seems to slow down as it moves to battery. It seems to move to full battery but often gets a light strike or not at all. It does not seem to have excess headspace and when the gun gets going subsequent strikes make a full dimple impression on the primer. Its just that first strike that is sometimes tough. Just added a new extractor. Ejector seems to clear the bolt OK. Does not appear to be any feed difference from the left or right side of the clip. I have tried original IMI clips and others with no difference in behavior. It seems like things work better when using a clip with just a couple rounds in it. Almost seems like the tension the clip spring places on the chambering round creates the failure when more rounds are loaded in the clip. Placing an dummy round in the clip and cycling seems to verify that the extractor is grabbing the rim to the first shot so it would seem that the extractor is flexing correctly and not hitting the side of the barrel. At this point the only things I can think of are barrel alignment or spring. Any ideas or advice would be greatly appreciated...
Problems Feeding UZI SMG
- Thread starter SWMod76
- Start date
navgunner
UZI Talk Life Member
My suspicion would be that your gun has a group industries bolt which in most cases are garbage. Buy a surplus bolt and see if it doesn’t resolve your issues. Worst case it’s a good spare to have so it’s worth the spend anyway.
It could possibly be your recoil spring assembly. For the first shot, the bolt is only held back as far as the sear holds it whereas subsequent shots will give the bolt more of a running start since the bolt will travel rearward beyond where the sear holds it. If your recoil spring assembly is worn out, it may not have enough stored energy to reliably strip and fire the first round on a full mag.
Perhaps try a new recoil spring? Is the gun an IMI produced semi that was converted to full auto by Group Industries? Or is it a Group Industries produced receiver that was either completed by Group or Vector?
If your bolt moves freely without drag (recoil spring removed and top cover installed) then my vote too, would be to look at the recoil spring assembly first.
Your description lends some confusion as to what exactly you might have
-IMI Model A with GI Registered Bolt
-IMI Model A RR converted by GI
-Group Industries RR (pre-Vector)
-Group Industries RR (Vector built)
Which is it?
Your description lends some confusion as to what exactly you might have
-IMI Model A with GI Registered Bolt
-IMI Model A RR converted by GI
-Group Industries RR (pre-Vector)
-Group Industries RR (Vector built)
Which is it?
Along with possibly installing a new recoil spring, make sure the gun is lubed well, especially if it is a new gun. The bolt slides much easier when it is greased or oiled well.
I would also try down loading the magazine and see if the bolt strips off the first several rounds easier.
I would also try down loading the magazine and see if the bolt strips off the first several rounds easier.
AKarms
Well-known member
Everyone has different opinions on this, uzis run better dry in my opinion. When you grease or lube them, all the crap from the spent rounds and carbon etc builds up and gunk’s everything up fast. I run all my uzis dry, and no wear or issues. By dry I mean I will oil them, but wipe all the oil away. Uzis weren’t designed to be run wet with oil or grease. Makes a mess and can cause issues with extractor getting gummed up
I understand your points. I don't run them wet, just a very light dab that spreads as it's fired. Not had any issues in 22 years. I also clean them thoroughly to remove any build up. I'm not concerned with anything making a mess, that's why I have plenty of rags.
Running them dry is not the recommended method,(nor is it for any gun) even though they will continue to perform. Do a search "Should an Uzi be lubricated" and see what you come up with.
Guns are a machine with moving parts that have surfaces that mate together during operation and a lubricant between those surfaces will always help it work better with less wear, whether it be a small amount of grease or a few drops of oil. (some guns like being really wet with oil, ie AR/M16, 1919a4).
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AKarms
Well-known member
I’ve got uzis in for repairs that I swear ppl have packed with red bearing grease lol, that’s the only point I’m trying to make. Yes a couple drops maybe or a dab here and there
barrelxchange
UZI Talk Life Member
Your extractor tension might be high with a full mag and the drag is giving light hits.
You should be able to move the extractor hook a little with firm finger pressure.
Another way to check is:
With bolt and barrel out of the gun, take a spent rd or unprimed and chamber in barrel, then take rd and barrel and try pressing on bolt face to clip over the extractor.
You'll see then how much force is takes to go in battery.
FWIW
You should be able to move the extractor hook a little with firm finger pressure.
Another way to check is:
With bolt and barrel out of the gun, take a spent rd or unprimed and chamber in barrel, then take rd and barrel and try pressing on bolt face to clip over the extractor.
You'll see then how much force is takes to go in battery.
FWIW
@navgunner thanks for the suggestion. I purchased what I was told was a surplus IMI bolt and that appears to have worked. At least it did for nine 32 round mags. The bolt that came with the gun had a mark stamped on it that I am unable to identify. Image below. I am finding some information that may indicate South African production?
Thanks, @navgunner. That seems to have done the trick. The bolt that came with the gun carries the stamp below. I am seeing indication of South African manufacture? Any ideas?
Thanks, @barrelxchange. I replaced the bolt with a surplus IMI and it seemed to solve the problem. The first bolt had an extractor in it that looked like the former owner had intentionally flattened to reduce the tension and allow it to more easily get over the rim and to battery. That was how the gun was when I received it. It was about 50/50 as to whether the first round would get to battery and fire. I got a new extractor that was so stiff it wouldn't get over the rim. This extractor was new mfg and had a very pronounced arc to it and was a tight fit in the bolt. This was a 100% no fire when added. The new IMI surplus bolt had an extractor in it that was about half way in between the original extractor and the new mfg one in terms of its arc and spring tension. This worked perfectly. I worked on the original bolt quite a bit but it seemed that no matter what, once in a while the bolt (when dry firing) would just sound like it wasn't dropping hard. Top cover appeared to be adjusted correctly and the bolt slid back and forth freely when inserted under the top cover without spring. The only thing I can figure is that the original bolt was hanging up when firing the first round or my spring was worn. New spring arriving today so I will try that. I very much appreciate your thoughts on testing the extractor by finger and a bolt push. Cataloged that for the future. I had actually built some rounds with no propellant and spent primers (painted green to identify them easily) and used these to see the first round primer crush on the original bolt.
Dirk Hawthorne
Well-known member
I was raised by WWII and Korean War guys.
They called a magazine a "clip." I grew up calling the magazine for my Marlin 22 a "clip."
Nowadays everyone has decided that calling it a clip isn't tactical enough. So everyone needs to be lectured about it.
Dirk Hawthorne
Well-known member
I run mine pretty wet with Mobil One and it does get skanked up with burned powder
But my Vector runs through 400+ rounds with no issues.
Sometimes before a match if it's dirty, I'll hose it out with WD40 and wipe it dry and then hit it with the Mobil One
I tried lubriplate grease one time and that totally didn't work at all, it's way too thick.
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