Gemtech QD UMP 45 Issues

[Jack_Bauer]

Has anyone ever had or heard of a problem like this? I saw this on HKPro site and since I have one on the way for my UMP 45 I am a bit concerned.
"A friend of my locally has had the same problem. But worst. He put his Gemtech 45 UMP suppressor on his factory HK UMP 40 barrel and it's wedged on there now. We both have tried to remove it...with no avail. A dealer down south has tried too.. No luck. And now it goes back to GEMTECH. So Ed Montana posted many moons ago about Gemtech and his barrels. I believe it's the suppressors. Time will tell us...Or
SHOT SHOW.....will..."

[kdcgrohl]

Not sure about that but my dealer had that can for his UMP with Ed's barrel and it would not fit. He sent the suppressor & barrel to Gemtech and they cut the barrel to make it fit. I took my UMP by there(German barrel) and the can wouldn't go on. I did want one, now I'm not so sure. Maybe one day when that project is back at the top of the list...

[mk23]

There is actually quite a bit of variance in the flanges of the German UMP barrels.

I have factory UMP barrels (40 and 45). And my Gemtech fit great on the 45, but not the the 40. It fits great on an Aftermarket 9mm too.

With some light polishing of the flange, it fit the 40 too. But don't force it if it doesn't fit or it will get stuck

[jcook119]

There is actually quite a bit of variance in the flanges of the German UMP barrels.

I have factory UMP barrels (40 and 45). And my Gemtech fit great on the 45, but not the the 40. It fits great on an Aftermarket 9mm too.

With some light polishing of the flange, it fit the 40 too. But don't force it if it doesn't fit or it will get stuck

I have the same issues on my barrels. It fits 45 and one of the 40 barrels, but not the other 40 barrel. Of the two it fits on, it is easier to put on/take off the one 40 barrel than on the 45 barrel.

[Eagle1*]

yes, same issue here. my dept issue 40 ump and gemtech supp is very tight to get off. i have to set gun upright and put my foot through the stock on the floor and pull really hard on the supp to get it to come off. i have tried oil/grease and that seems to make it worse to get off.

i called gemtech when we got the supp and they said to use some emry cloth on the barrel lug to slighty make the barrel smaller to get it on/off. never did it so i seldom use it for swat!

[Cruzzer]

When Ed Montana at HDPS made my UMP conversion he recommended I get my barrel threaded as he was not too crazy about the way HK's set up was for their barrel/suppressor attachment point, the guys at Gemtech said the same thing. So when my stamp arrived I removed the barrel and sent it to Gemtech and let them do the threading for a reasonable price and a three week turn-around. First class job all the way around from HDPS and Gemtech.

Now there is a certain cool factor to the flange mount but the only time my suppressor has gotten stuck on my barrel is when I cranked down on the can. I needed my son to help me screw it off and have since learned to "hand tighten only".

If you go the threaded route get the shims just in case the zero changes from suppressor on to suppressor off. The nice thing about the threads is I'm not tied to a HK mounting system. Gemtech can convert the UMP back to threads if it becomes an issue. I'd highly recommend you let them do the threading. I had a local smith thread a barrel for a Blackside. The thread was correct but the profile was not and subsequently lead to the threads stripping out on the can. I sent everything back to Gemtech and have been 100% satisfied with the results. Other then that enjoy.

Semper Fi! Cruzzer

[Jack_Bauer]

I just wanted to give an update on my new Gemtech UMP 45 suppressor. I got it this week from my dealer and installed in on my UMP 45 with factory HK UMP 45 barrel with no problem what so ever. It took all of about 4 seconds to install. This is a great suppressor and I would highly recommend it on the factory HK UMP 45 barrels.