[MKEMP5K]

Hello all...I am kind of dismayed and all. I have a UMP and two 45 cal cans for it...After zeroing the HK if I am not within 10 yards of the target silhouette the bullets completely miss the target...at 10 yards they are about 10 inches off at 2 Oclock...again, at 25 they I completely miss the man silhouette target ...The cans are two diffrent models, one can be shorten and used in that configuration. As far as I can tell there are no baffle strike. Any ideas, because I am fresh out here! Thanks in advance...

 

[kaotic504]

i’m going to assume you do not have the flange barrel. If it has been a threaded barrel, I would check to make sure the threads are concentric. Also, make sure you’re running a fixed spacer and not a regular booster on your suppressors. I have never had a problem with getting on target on my USCs that I had cut and threaded.

 

[Tactical_T]

What suppressors are they and what type of attachment are you using?

 

[LEEF]

Pretty common with the UMP. IMO and experience, it is a HK that doesn't like to be suppressed. Too much POI shift for a barrel that is held in a polymer receiver with 1 pin.

 

[MKEMP5K]

i’m going to assume you do not have the flange barrel. If it has been a threaded barrel, I would check to make sure the threads are concentric. Also, make sure you’re running a fixed spacer and not a regular booster on your suppressors. I have never had a problem with getting on target on my USCs that I had cut and threaded.

Sorry for late reply...I am overseas right now...I do have a threaded barrel on the UMP...I have not check for concentric thread/barrel and I do run the booster on it.

 

[MKEMP5K]

What suppressors are they and what type of attachment are you using?

One is ACC Tirant .45 and the other Ti-rant 45M and I do use the booster on that too! They are threaded to the barrel...

 

[MKEMP5K]

Pretty common with the UMP. IMO and experience, it is a HK that doesn't like to be suppressed. Too much POI shift for a barrel that is held in a polymer receiver with 1 pin.

Its a shame I spent so much money and time and Stamp, if i cant correct this issue here...

 

[ToyCop]

As mentioned above, you need a fixed barrel spacer to use those cans with the UMP. POI shift with my 3 lug and Hybrid can is less than one inch.

 

[MKEMP5K]

As mentioned above, you need a fixed barrel spacer to use those cans with the UMP. POI shift with my 3 lug and Hybrid can is less than one inch.

Thanks for the info...I am overseas right now and will give it a try when I get back...cant wait...thanks...

 

[biggmac1]

One is ACC Tirant .45 and the other Ti-rant 45M and I do use the booster on that too! They are threaded to the barrel...

Why are you using the booster, given you are shooting from a fixed barrel?

 

[MKEMP5K]

Because I am not familiar for the reason of the booster...I have a feeling your going to tell me...

 

[mak0]

Because I am not familiar for the reason of the booster...I have a feeling your going to tell me...

Pistons/boosters should never be used on a fixed barrel. They are only for firearms where the barrel has to move to unlock, such as pistols with a titling barrel. You can use the piston itself but you just have to replace the spring with a fixed barrel spacer.