UZI build questions

[Jones]

To my original reason for joining the forum;
I've decided to try my hand at building a semi-auto, closed bolt Mini pistol and this seems to be the best place for solid information and level-headed answers w/o BS.

A good place to start is by finding a clear set of dimensioned blueprints. Lots of prints around for the full-sized but nothing so far on the minis. Any suggestions on where to go or who to contact for them and semi-auto parts would be appreciated.

Second is choice of calibers. Seems like there are lots of 9mm around so I thought it would be interesting to build one in 45 ACP. Don't want to put that much effort into building one only to find that magazines cost more than
kits are going for. Or will my claim to fame be in having the only UZI semi-auto single shot known to exist.
Reasons for there being so few 45 ACP guns? 9mm just being the more wide-spread use caliber or did the 45 ACPs have design or reliability flaws?

Here are a couple of my earlier attempts at gunsmithing and building:
Draco AK pistol into BFPU Krink. This included making my own hinge block 'cause Krinks' top covers don't come off, they just swing up for disassembly. Barrel shortened to 210mm. Shorten gas tube and remake gas tube end including making dies to iron out and reform gas tube piston guide ribs. Shorten upper and lower hand guards then making new front and rear hand guard sheet metal.
Study lots of AKs in action pictures to see where the wear marks on the finish should be to get that seen-lots-of-action look.

Beretta 92F reworked to accept 92F Compact slide. Full-sized frame with the shorter slide seems to be the best of both worlds for me. I also did away with the last round, hold open 'feature'. In a tactical situation, nothing says "Hey everybody, I'm out of ammo" like having the slide stay back after the last round is fired.

 

[slimshady]

AFAIK, unless you get or make a modified grip assembly that takes US M3 Greasegun mags the sole source of .45 mags that fit a stock magwell is Promag.

https://promagindustries.com/uzi-45-acp-22-rd-blue-steel/

Promags are hit and miss, over all platforms some people swear by them, others at them.

As for the popularity, UZIs tend to eat through an ammo pile pretty quick, even in semi. At least in normal times, 9mm is cheap compared to .45. In FA, I would think the heavier recoil and lower mag capacity would cancel out any perceived advantage in "stopping power." I mean, a cluster of 5 9mm FMJ to the upper torso is not much different than a group of .45 caliber holes in most instances. There is also the issue of supply chain for military users, 9mm is usually present, .45 not so much. .45 was/is mostly a US consumer thing, worldwide it is rare to see a military firearm in that caliber with 9mm being the overwhelming choice of most military and police subguns. Adding to the cost is most UZIs imported to the USA were 9mm, making one a .45 requires purchasing conversion parts on top of the cost of the gun.

"In a tactical situation, nothing says "Hey everybody, I'm out of ammo" like having the slide stay back after the last round is fired." Nothing makes you go "Oh Shit!" in a tactical situation like really, really needing to fire a shot and getting a click instead...

 

[Jones]

All good points slimshady.
I think I'll stick with 9mm. That's IF I go ahead and build. I'm still seeing what semi-auto Mini UZI parts availability is like.

Tactical situations: I've found the best way through them is to avoid getting into one in the first place. However, if someone is insistent that I join in, my 92F-SC is my choice. We know each other well and usually-- if I can see it, I can hit it.
Been shooting a long time now and from tin cans and paper targets as a kid to firefights in Nam, I know to try to make every shot count and can even manage keep track of rounds fired.
May not be everyone's approach but it works for me.

 

[slimshady]

The bolts are damn near impossible to get unless you have massive amounts of cash stuffed in your pockets. Same for the folding stock assembly. Probably best and actually cheapest to buy a complete parts kit even though they go for lots of $$$. Some info and drawings here, procedure for making one from a full size and individual parts. Prices listed are a decade or so out of date, still kick myself for not grabbing some parts back then...

http://www.uzitalk.com/reference/pages/buildminiuzi.htm

 

[Jones]

In my search for parts, I'm running across some items that have me confused.
There are obvious differences in FA and SA trunnions, bolts, lower grip assemblies but what differences are there in parts like barrels or feed ramps? Top covers?

 

[slimshady]

Like the full size, the Mini uses the smaller diameter semi auto bbl spec for the chamber end to fit the smaller SA spec receiver parts. The FA spec bbls are full size and the FA feed ramp lacks the restrictor ring the reduced diameter chamber end fits through. This prevents a stock SMG bbl from just dropping into an SA to convert it to an SBR.

The top cover is ratcheted like the full size, the semi is not. Removing the spring and pawl converts it to semi spec. The OEM topcover has no indent for the ejection port, some are made from cut and rewelded full size covers and those will usually have the indent.

AFAIK, the only difference in the lowers were the selector markings, everything else was the same as the full size.

Unlike a full size UZI, the mini doesn't use a blocker bar and slotted bolt. On the FA, the bolt has "feet" sticking out the front that engage the sear, and the trunnion and receiver are clearanced for them to fit when fully forward. The SA model lacks these cuts.

Have you perused the library? Lots of photos illustrating differences and variants of the 3 sizes and parts thereof.

http://www.uzitalk.com/

 

[Jones]

Yep, been through as much as I can find related to minis. One link I ran across describes what makes a mini a mini. Very handy information to have.
I also found a couple of sources for small parts including locating a stripped semi-auto mini bolt I picked up for what I considered a great price. All the internals to complete the bolt are already on order.
Found a mini top cover and gotta find the internals for it too. Trying to figure out little mechanical details like how the minis are cocked since the bolts don't seem to have the cut out for the cocking lug.
I'm continuing to look for a semi-auto lower grip assembly so no one gets excited about a third selector position. I can positively block getting to the FA position but why not just do it right to begin with.
When I'm done I want this build to function and look "factory" so taking my time is worth it in the long run.

 

[slimshady]

Only the Micro uses a cutout, due to it's shortness. The Mini is like the full size, it just sticks down in front of the bolt. On the topcover, IIRC the sliding dustcover is shorter, but the rest of the small parts are the same as the full size. IMI apparently wanted as few new/different parts for the Mini, probably to save costs. Why change something when the old one works just fine. Would that Bill Gates subscribed to that philosophy...

 

[Jones]

Thanks for that clarification, saves me a bit of machining.
I agree with your philosophy; A different color scheme on a webpage doesn't constitute an upgrade.
Functions that don't work shouldn't be referred to as "It's not a defect, it's a "feature".
And always remember; "New & Improved" usually isn't either.

 

[slimshady]

I was thinking along the lines of "We've put that feature/command/button in the exact same place for 15 years, let's hide it over there someplace no one would ever think to look for it there in the new version!" That's probably how bonuses are determined at Microsquish!

 

[Jones]

I tend to try to keep up to date and get rid of unnecessary junk so as not to clutter the landscape... so "Recommended For You", Lists of my purchases from the dawn of time, or any site or software defaults that act like it knows better than me what I should be interested in. Farcebook and all it's spawn be damned; I still write letters and know how to do long division.
I'll start calling them a smartphone when I yell "Where's my frickin' phone?" and it answers "Right here, stuck between the couch cushions".