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And so it begins: 9mm USC to 16" UMP Conversion and links to ALL UMP Conversion Info!

85471 Views 117 Replies 37 Participants Last post by  Gokoolab
And so it begins: 9mm USC to 16" UMP Conversion and links to ALL UMP Conversion Info!

Well I *think* I’m the first person to undertake this particular conversion although I believe others have already done the 9mm UMP conversion with the 8” Barrel (feel free to chime in here guys! :)).

My main purpose here is to actually create a place with ALL the links and other information needed to complete a DIY USC to UMP conversion of any caliber.

First let me say this article is in NO way to say that you should not use any of the vendors that offer this conversion, rather than simply a place to find links and other pertinent info for those of us who really enjoy cutting up a brand new gun :D

Links to Machining Information for Conversion:
A VERY Basic Guide, read this first to get an idea of what needs to be done:
http://tradecraft.us/Firearms/HowToUMP/HowToUMP.htm

A VERY DETAILED Guide, read this when you have your parts and are ready for specs!
http://home.comcast.net/~UMPlower/

UMP Foregrip Vent Location:
http://myweb.cableone.net/jsheffi31/Slots.htm

UMP Mag Well Template
http://hkpro.com/forum/attachment.php?attachmentid=1743&stc=1&d=1188954110

UMP/USC Parts Comparisons (See Gallery)
www.tacticalexcellence.com

NFA Information that may be helpful when doing conversions:
http://www.top-notchparts.com/atf_nfa_letters.htm

Links to Suppliers for Conversion Parts (The ones I personally used)
Adam Webber HK4Evr www.hkparts.net
Ed HDPS www.hdps.org
Top Notch Parts www.top-notchparts.com
Other Suppliers of Note:
Gordon Miller - www.hkspecialist.net
Phil Flack - [email protected]
Clyde Armory - www.policeguns.com

Now that I’ve got the basics out of the way I’m going to document what’s needed to do this conversion AND change calibers. I couldn’t find a lot of the information I needed easily such as how much I needed to change the bolt, 16” barrel suppliers ect. Let me start off by saying that while the regular 45ACP UMP conversion is actually very reasonable if you buy parts from the suppliers listed above, changing calibers can be VERY EXPENSIVE; you have been warned :D

Caliber Specific Conversion Parts:
Bolt Assembly
Barrell
Magazines

I bought all of the above parts (and parts for all my other guns) from Adam Webber (www.hkparts.net) and I can’t say enough about him and his service; amazing! Now before you go and call/email/homing pigeon ect Adam, he doesn’t have any more 9mm parts but does have plenty of 45 and I believe even some 40 parts. I will warn you that in my experience the 9mm parts may as well be made from un-obtainium as I had a HELL of a time finding ANYTHING in 9mm.

By now you are asking "Why the hell would he want 9mm?" Well the answer is relatively simple; I like 9mm :) All of my other guns (with the exception of the AR) are 9mm.

I was able to find ONE supplier that made a handful of 16” .40/9mm barrels and that was Top Notch. According to the gentleman I spoke to when I ordered he believed I was the first to buy one of the 16” units but still had a few left. I also bought an 8” HK barrel from Adam on the odd chance that someday Michigan will allow SBR (HA!).

The Parts:
HK 8” UMP 9mm Barrel, 9mm Magazine, 9mm Bolt Group (.45/.40/9mm all use the same recoil rod BTW) and some extra barrel pins.



Now that I’ve got these parts I’ll start to document what you need to do to the bolt to assemble this thing as well as updating this when my 16” Barrel arrives and how the gunfunctions/looks ect. I hope this post will help some people not have to search for hours to find information like I did!
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Congrats on finding the parts and going through with the 9mm UMP build. I refuse to pay $1500+ for one bolt assembly, otherwise I would have done one a long time ago. I wish someone like Ed or TN would step up to the plate and make a few bolts for us instead of having to get bent over by the parts dealers.

Thanks,
James
 

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Yes, I got the bolt from Adam. It was like finding the Holy Grail :) As for the barrel, I've been sitting on it for almost 2 years. Which is a lucky thing I had since the TN 9mm barrels appear to be defective. I went out to the Top Notch site earlier this evening and the only barrels I see offered are 45 ACP. I did not see any references to 40 or 9mm.

Have you tried posting on TB's board? He usually answers posts from folks with problems, maybe he can get this back in front of Wade. I'd like to see them fix these barrels, because I was thinking about buying one and having it cut down and 3-lugged for my Gemtech Raptor.

In any case, I hope you get the issue resolved. Meantime, have you tried your factory barrel? Does the conversion work OK with it?

Thanks
James
 

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I got through to TN today and ordered one of the 16" 9mm barrels. GTPprix, give them a call tomorrow or Wednesday. From what Todd said on his board, and what the lady at TN said today, they are getting a new batch of the barrels late this week. Maybe one of the new barrels will fix your issue. Start calling them tomorrow and see if you can find out what's up. Meanwhile, I'll let you know once mine comes in and I have a chance to test it.

Thanks,
James
 

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Got my TN 9mm barrel Thursday. It has some light finish wear, and had unburnt powder flecks in the barrel. I assume that was from test-firing, unless I was sent GTPPrix's old one :)

I took it out on my lunch break yesterday, installed on my TE conversion. I ran some Georgia Arms 147-grain and Winchester White Box 115-grain through it. Here are the results:

Mag 1: 27 rounds GA - no malfunctions
Mag 2: 31 rounds WWB - 2 failure-to-feed
Mag 3: 30 rounds WWB - 2 failure-to-feed
Mag 4: 30 rounds WWB - 1 failure-to-feed
Mag 5: 10 rounds WWB - no malfunctions

The 5 FTFs were all the same type. Apparently the lip of the casing was catching on the "ramp" on the top of the barrel. The round would stick in that position, bolt partially open. I think a polishing job on the ramp might be in order. Jams were different positions in the mag, no "last round only" or other detectable pattern.

I am going to send it to Mark at TROS for a chop and 3-lug job. I assume he can do the polish job as well. I'll report back when I get it back from him and do another test.

Thanks,
James
 

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Mark has my TN 9mm barrel in hand. He is going to polish the ramp for me. He said that it is thick enough to do an integral 3-lug, so we'll see what happens. I'll report back when he gets it done.
 

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Unfortunately I was too impatient to take a pic before I installed it, but next time I take it out I will do so.


















A couple with my Gemtech Raptor







Mark did an incredible job, as always. The lugs are integral, no thread-on adapter needed. The barrel fits into the receiver perfectly, no problems. The Raptor locks on perfectly too. This is the third barrel from Mark that I have (UZI and P9S 9mm are the others), and I love the fact that I can use one can on 4 guns.

He also polished off the sharp edge of the feed ramp, so it is rounded like a factory barrel. I hope to run some rounds through it tomorrow or Sunday, and will post a report when I do. If the polishing eliminates the feed issues that GTPPrix and I experienced, then we have a winner for folks looking for a barrel to complete their build.

Thanks,
James
 

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Range report

Took the gun out today to test the barrel. Here are the results:

Mag 1: 30 rounds of WWB - 1 failure, 6th round from the bottom - case edge was crushed on one side like before, round was stuck in the chamber, no primer hit. Had to pop it out with a cleaning rod. I need to check the chamber for scratches.

Mag 2: 30 rounds WWB - no failures

Mag 3 (with Raptor): 30 rounds Special K subsonic - no failures

Mag 4 (with Raptor): 30 rounds Special K subsonic - no failures

Mag 5 (with Raptor): 30 rounds Hornady XTP JHP subsonic - no failures

So, 150 rounds and one failure, much better results than with the original, unaltered barrel. But the fact that the failed round was stuck in the chamber bothers me. Whatever the edge caught on wasn't enough to keep it from feeding in part-way, which jammed it up good. I guess I'll have to run a few more mags through it before I consider it reliable enough to zombie hunt with :)

Thanks,
James
 

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Call Top Notch and order one of the 16" 9mm barrels. When you get it, send it to Mark McWillis for the chop, polish and 3-lug work.

Gordon Miller is advertising UMP 9mm bolts on Sturm now, but they are higher-priced than Adam was selling them for.

Thanks,
James
 

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I have always assumed that the suppressor would not fit since the 40/45 B&T flash-hider won't fit. I guess I'll have to find a UMP suppressor and see if I get the same result as GEBEBPRS.

Thanks,
James
 
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