45 USC plus 45 UMP kit equals?

[wig]

Riddle me this.. with that formula (USC plus full UMP kit as sold by various vendors) ... will that be everything needed for the conversion - I'm guessing yes - but the most important part of the question - will it shorten the process and remove a majority of the machining?

Does anyone have a rundown of steps given a full kit purchase?

One location I found that had a kit shows this (supposedly everything but the receiver). Given that, what has to be done to make the USC receiver work? (also I assume that's the upper receiver they mention).



Options-wise, this looks like it includes an SBR and a 3-mode selector - will that have everything required to do a full auto conversion, or do I have to gut the semi equipment from the USC and move them.

Sorry if these are fundamental to all here, but I really want to look at doing this project - just not sure what's truly involved (and yes been reading for weeks).

Cheers!

[wig]

I'm sorry - one more part to the question - if I wanted to leave the 15" barrel, are they interchangeable with the SBR - without doing any other work, or would that be very involved?

Cheers again!

[mikecleonard]

Wig,

First off...if you are not LEO, or Military, there is no way for you to legally convert a USC into a full auto UMP. Full auto sears and lowers that are made before 1984 are available for HK94's/MP5's...but the UMP is way too new to have any fully transferable parts available for it.

The only parts you would need from a UMP kit like you have pictured are the barrel, folding stock, and lower receiver. The bolt that comes in the USC will be fine to use in the conversion...or you could use the UMP bolt from the kit with just a little modification. Either way, thats up to you and you will still end up with an extra bolt that you could try and sell. You could also sell the short UMP barrel if you plan on sticking with the 16" USC barrel. If you decide to do that...let me know as I'll pay a good price for it! =O) The kit won't do anything for making the conversion work any easier aside from allowing you to get all the UMP parts you will need in one purchase.

When you send your USC rifle and UMP parts to have a conversion done, the person doing the conversion will have to do the following:

- Transfer the semi-auto USC fire control group into the UMP lower receiver
- Cut some material from the front hooks on the UMP lower so that it can attach to the USC upper receiver
- Mill the fore grip vents in the USC upper to match the look of a UMP
- Create a "Stock Block" that allows the UMP folding stock to fit with the USC upper receiver
- Widen the magazine opening in the USC upper receiver so that the wider UMP mags can fit into it.
- Engrave your personal information into the upper receiver if you plan on registering the gun as a Short Barrel Rifle with the ATF. (Not needed if you plan on using the standard 16" USC barrel)

Also, yes you can swap between the short UMP barrel and the stock USC 16" barrel if you want. All you have to do is knock out one roll pin in the receiver and the barrel will come out...takes about 5-10 minutes.

I think thats everything. I used Ed at www.hdps.org and would Highly recommend him for a conversion...he did fantastic work on mine.

Good luck!

-Mike

[wig]

Thanks tons for a detailed writeup. The first part's a deal killer - :( so it really boils down to mag capacity and looks.

All that being said, for the sake of a full-circle education, if I happened to be a SWAT member and bought said kit, took a USC - left the UMP kit parts as is - is it a plug and play with no modding? That's what I keep having rattle around in my head. Since I can't certify it - it's a non issue, but for personal gratification would love to know.

Thanks again!!

[mikecleonard]

Wig,

Glad I could help. As far as your last question...I think that in order to have an actual UMP bolt work in the USC upper receiver, some very minor work has to be done to the bolt but I'm not quite sure exactly what has to be done. Also, the plastic hooks on the front of the UMP lower that holds it to a UMP upper have to be enlarged to fit with a USC upper so the kit wouldn't be an exact match right from the start. Really the only thing that is a dead match between the UMP and USC is the barrel. Most of the other parts need minor fitting work.

-Mike

[swenk]

Putting a fullauto lower on a USC would be a really really really bad idea.
You would have to cut a notch in the upper receiver for the auto sear, and once you do that you have just created an illegal machine gun.
Having it isnt worth the prison time, Swat team member or not.
:)

[Jasongar8]

If you are SWAT shouldn't you already have plenty of full auto stuff to play with without having to ask about how to do illegal conversions? Seems like more and more "law enforcement" personal don't really know the laws?
-Jason G

[HKNC]

Law enforcement and military aren't even allowed to convert a USC to full auto. A class 2 with intent to sell could but I don't see that making any sense......

[wig]

EASY fellas. I said "IF" as in hypotehtically. Of course higher-end mil/pol folks can get whatever they need (given taxes :) ) without hacking. I was just trying to understand how this all goes together. I'm an engineer - and love to understand the full depth of a situation.

Thanks again - and Mike, that's about the conclusion I came to on my own.

Best.

[Renegade]

Generally you do NOT want to use the UMP B/C in a USC. It takes a bit of modification (you need a mill, or the best dremel skills in the world), and it does not work with USC barrels.