JustinJ
Member
I completed my HK UMP build over the weekend and got a chance to run it.
Total cost broke down as follows, excluding tools:
HK USC new(black)-$1300
HK FBI Lower- $300
HDPS Stock Block: $200
UMP Mag - $60
US Mag follower and floor plate (2 992r parts) - $25
UMP Armorers Manual - $25
Top Rail: $40
Bottom Rail: $30
Top Notch US Stock (1 922r part) - $100
SS Stock Hinge - $20
total - $2100
Swapping the trigger group wasnt terribly hard. The armorer's manual turned out to be of limited use for this so instead i found a good how how to guide with clear pictures on HKPro. I opened the hooks of the UMP lower with round files and got a nice fit. The hardest part was opening up the magazine hole in the bottom of the upper. I tried to use a x,y cross vice on my table top drill press but there wasnt enough room to properly insert the upper in the vice grip for proper orientation. Instead i attached a scope base to the top rail and held that with the vice. Unfortunately there was excessive wobble while milling so my cuts werent nearly as straight as I'd like. The polymer material of the upper flexed too much. Luckily the magazine is secured by the lower mag well so the upper receiver opening isnt important to functioning so long as the mag can seat properly.
I took her to the range yesterday and ran about 150 rounds of federal FMJ. It ran flawlessly and i was more than happy with performance. Looking back however i do wish i had sent it off to be converted professinally as it is fairly inexpensive. The biggest reason i did not was not wanting to deal with the hassle of mailing it. I had a bad experience before. Plus i really didnt want to wait so decided to do it myself. Although performance is perfect collector value would be higher had i let a professional do it. Plus i still need the vent cuts at the foregrip. My next step is to SBR, get a UMP length barrel and silencer. Instead of the true UMP 3 lug barrel i'm going to either chop and thread my barrel or buy one arleady done. I want a can that will fit on my .45 pistols as well.
Total cost broke down as follows, excluding tools:
HK USC new(black)-$1300
HK FBI Lower- $300
HDPS Stock Block: $200
UMP Mag - $60
US Mag follower and floor plate (2 992r parts) - $25
UMP Armorers Manual - $25
Top Rail: $40
Bottom Rail: $30
Top Notch US Stock (1 922r part) - $100
SS Stock Hinge - $20
total - $2100
Swapping the trigger group wasnt terribly hard. The armorer's manual turned out to be of limited use for this so instead i found a good how how to guide with clear pictures on HKPro. I opened the hooks of the UMP lower with round files and got a nice fit. The hardest part was opening up the magazine hole in the bottom of the upper. I tried to use a x,y cross vice on my table top drill press but there wasnt enough room to properly insert the upper in the vice grip for proper orientation. Instead i attached a scope base to the top rail and held that with the vice. Unfortunately there was excessive wobble while milling so my cuts werent nearly as straight as I'd like. The polymer material of the upper flexed too much. Luckily the magazine is secured by the lower mag well so the upper receiver opening isnt important to functioning so long as the mag can seat properly.
I took her to the range yesterday and ran about 150 rounds of federal FMJ. It ran flawlessly and i was more than happy with performance. Looking back however i do wish i had sent it off to be converted professinally as it is fairly inexpensive. The biggest reason i did not was not wanting to deal with the hassle of mailing it. I had a bad experience before. Plus i really didnt want to wait so decided to do it myself. Although performance is perfect collector value would be higher had i let a professional do it. Plus i still need the vent cuts at the foregrip. My next step is to SBR, get a UMP length barrel and silencer. Instead of the true UMP 3 lug barrel i'm going to either chop and thread my barrel or buy one arleady done. I want a can that will fit on my .45 pistols as well.