Micro Uzi Carbine Build

[amphibian]

It looks (reciever) orignal. maybe a super early pro to-type.

I agree. It has the typical "UP" serial number prefix.
Very interesting lower. Never seen one like that w/ the angled area that meets the receiver but flat in the back like the MINI and FULL size.
Also has the interesting "semi ribs" in the rear.
Thanks for the pics!!

 

[suka5168]

I'd like to work on a Trunion design this week. Any details on this is gladly appreciated. The Micro/Pistol has a different treading on the trunion and to save cost I plan to use the standard FS/mini barrel nut.

pics , dimensions will be needed as well as any notes (weld areas, etc.)
Thanks.

 

[suka5168]

Four parts needs to be US made.
Reciever and Trunion right off the bat.


(1) Receiver*
(2) Barrel*
(3) Trunion*
(4) Bolt
(5) Op. Rod*
(6) Trigger
(7) Disconnector*
(8) Buttstock
(9) Pistol Grip*
(10) Magazine body*
(11) Mag Follower*
(12) Mag Floorplate*
(13) Trigger Group Housing
(14) Sear

*avalible options for USA parts

 

[suka5168]

some dims needed......
please
Heres a pic i drew this afternoon, I dont have a Micro so this is my interpretations of the internals?.... hope its correct. if not please advise.
I do prefer to work with Millimeters but inch conversions is OK
25.4 mm per inch

 

[Brian Ski]

All American dims... Cuz that is what I am..

1 1.230

2 1.778

3 5.918

4 2.177

5 .742

6 .629

7 1.386 From top of trunion it is flat where threads are milled off.

8 2.287

9 2.296

10 5.470

11 .791

12 2.771 My restrictor band looks thinner than your pic.. it is about .234. The base looks similiar but looks like it was machined from the rear to make it thinner... (the front of the ring is in the same place if you follow)

Take the dims and round up or down a couple thousands to match the metric equvilent... I am not completely accurate with a caliper... Especially on rounded corners, or things that cannot be measured squarely...

Hope this helps.

 

[suka5168]

#12... Just wanted to make sure it was to the end of the barrel , not the feed ramp?

 

[Brian Ski]

#12... Just wanted to make sure it was to the end of the barrel , not the feed ramp?

Glad you asked.... 2.855 from the chamber end of barrel... Wasn't clear I measured from the restrictor ring the first time....

BTW get the pics???

 

[suka5168]

I want to get a detail of the trunion, so i can do some designs on paper and send it to get milled. That should be my priority this week.

But any info is welcomed

 

[suka5168]

The front of this will be the regular F/S trunion threading.

 

[Brian Ski]

Lets try this in a couple steps... It is hard to see what is going on without taking the trunion out of the gun... One thing is different... Where you say the back top of the trunion is .060 To the best I can with a mic it is .060 BUT the front measures .090 (where the threads are milled off) I think it may be stepped somewhere by the reciever...

BTW the front of the trunion is covered in a layer of tin... Like the metal used in the sides of the gun... BTW the wall thickness of the reciever is .047.

I am getting just a few thousands less than 17mm for the trunion id... after conversion it is like 16.61mm.

Trunion length front to rear... 1.209 plus the tab.... 1.300 total length (including tab)...

Length of exposed threads .375... but remember the front of the trunion is covered by tin add .047 from above. (wall thicknes if you follow)

Height of alignment tab it .096 but that does not include threads.. They are milled off tab... The tab is flush with id of barrel if you follow... Dam just can't put in words what a pic would show!!!!

BTW od barrel diameter that Barrelxchange made for me is .645.

Let me know if that fills in some blanks.. The rest of the numbers look good...

 

[Brian Ski]

Your width dimension of 1.328 I am getting a little smaller 1.291. That is the ID of the reciever... BUT the trunion is smaller.. It looks like they took a piece or .047 tin and as you are looking from the top... Barrel pointed at you.... They wrapped the trunion on the front and left and right sides... So the trunion would measure 1.291-.047 form one side and -.047 for the other...

Not sure why they did that. If it was me I might skip the tin deal and make the trunion a full size... Without the tin... I was going to say like the full or mini size... But they have a front grip and I can't see how they are done...

I sure as heck hope you are confused now!!!

 

[suka5168]

I sure as heck hope you are confused now!!!

Im with ya, I can follow what you are saying.

Seems the tin is used to shim the trunion before it is welded or to save weight.

My trunion will be installed in a full sized repair channel, so the width my be larger. also will be using a F/S barrel nut 25x1mm.
As the Micro nut are a bit costly.

 

[Brian Ski]

Im with ya, I can follow what you are saying.

Seems the tin is used to shim the trunion before it is welded or to save weight.

I doubt if it would save much weight... But don't know if it was used for reinforcement... kind of strange...

My trunion will be installed in a full sized repair channel, so the width my be larger. also will be using a F/S barrel nut 25x1mm.
As the Micro nut are a bit costly.

Yea the nut is more (I just got a spare from Vector $20) but you may be opening a can of worms... The Full size nut is almost twice as deep... So you will have to make the trunion longer.... If you do that the barrel won't reach the bolt....You can't recess the trunion further so you will need a custom barrel or maybe cut the f/s nut down... It might look a little crappy and I am not sure if it threaded as deep into the nut as the pistol nut... Hmmm

 

[suka5168]

going to use a 16" barrel .

grind of the original barrel stop band and reweld a new band in it new location.

 

[Brian Ski]

going to use a 16" barrel .

grind of the original barrel stop band and reweld a new band in it new location.

ooohh Someone has been doing some thinking!!!!

Good luck!!!

BTW does the barrel have a larger OD than the pistol??? Going to turn it also??? I think I gave you the Micro barrel od above...

 

[suka5168]

All my toys are at my Parents house. So Im just playing by ear.
So i need all the help I can get with measurments.

 

[suka5168]

Do you think the "tin" is used as a housing to hold the trunion in place? The sides and bottom looks bent inwards with tabs?

If so i will need to redo some work with the drawing.
Thanks

 

[Brian Ski]

Do you think the "tin" is used as a housing to hold the trunion in place? The sides and bottom looks bent inwards with tabs?

Yes the "tin" is used to hold the trunion in place but I don't know why... Maybe it was easier or stronger to weld the tin in place instead of spot welding the trunion... If you are custom making the trunion I would skip the tin and go with a full size trunion...

 

[suka5168]

This should be the final Trunion drawing. It includes the Trunion, Barrel collar band, and Front Plate.

 

[Brian Ski]

Looks pretty good except for a couple of small drafting errors... But we won't get into that. I would give you an A. That is because I am a nice guy!!!!

Only thing I can comment about is on my Micro the trunion is stepped...As far as I can tell... Looks the same as yours inside the reciever but the outside is just a hair taller so the barrel hole is not quite as thin on top... Not sure if it worth changing depends on how the barrel nut catch fits...