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Base/Stock Block USC to UMP Conversions

Full Weld-On USC to UMP Conversions

UMP-SD Custom Builds

USC to UMP General Services

  • We can set you up with a UMP clone that suites your needs and budget!
  • We can add the UMP folding stock and grip ergonomics.
  • The conversion allows you to use high capacity, double stacked UMP magazines.
  • UMP ejection port stock catch and cooling vents can also be added.
  • The ultimate civilian legal UMP clone can be built if you are in a state that allows you to register your gun as an SBR or Short Barrel Rifle. Contact us for details on From 1 SBR registration.



The USC to UMP conversion is very popular with HK owners and enthusiasts. The basic USC is not as versatile and not nearly as ergonomic. What you gain by doing the UMP conversion is not only looks and authenticity, it’s also a better feeling and better handling gun. The feel of the grip itself is much better and the folding stock option is a big improvement over the fixed USC stock. If you are in a state that does not allow the folding stock, it is still worth it just for the better ergonomics of the UMP grip. These ergonomics greatly improve the shoot-ability and feel of the USC.

For completed USC UMP conversions for sale/ready to buy, contact us to see what we have in stock:

Base USC to UMP Conversion Service (Stock Block Type)


  • Milling the forward barrel cooling vents in the USC receiver to match the venting of the UMP
  • Milling the magazine well of the USC to accept the larger UMP magazine
  • Dying of the gray polymer, USC to the dark black HK color
  • Milling of the forward receiver hooks on the UMP lower to accept the USC upper
  • Filling and false pinning of the forward section of the UMP lower for 100% ATF legal piece of mind
  • UMP stock catch option, just like real UMP
  • Dis-assembly and reassembly

For completed USC UMP conversions for sale/ready to buy, contact us to see what we have in stock:


This “fuse job” conversion offers the most realistic, true to the real thing, conversion a civilian can own! The plastic welding “fusion” procedure requires lots of time and patients as well as plastic welding experience and jigs.


  • All of the above “basic services”.
  • Welding the UMP rear section to the USC receiver and adding the stock catch to the side of the gun.
  • Re-marking/Engraving the HK UMP correct markings

For completed USC UMP conversions for sale/ready to buy, contact us to see what we have in stock:

HK UMP SD Custom Conversion

Custom UMP SD Conversion Service Options:

  • Magpul, HK or other custom buttstock
  • Shaved fixed sites and full length top rail
  • Threaded barrel for use with various existing suppressors
  • Cut out enlarged/modified foregrip using Magpul MOE parts
  • Custom cocking handle

The UMP SD is a custom project so you can pick the options you’d like to go with. Example pricing is as follows:

For completed USC UMP conversions for sale/ready to buy, contact us to see what we have in stock:

Additional USC to UMP Services

Additional customization options are available.
Click the links below to see the corresponding service pricing and to add services to your cart.

What to Expect

  • NO FOREIGN MATERIALS USED when welding or plastic fusing
  • NO FILLERS or putty, only melted nylon from the actual HK polymer
  • Bondo/body fillers, epoxy and other “quick fix” materials will crack, flake and compromise overall finish/durability. You will not find this in our work!
  • No waves! Smooth flat even surfaces ( Straighter than the factory since most mold waviness is removed during the process )
  • No pinholes in final finish
  • DuraCoat Firearms Finish w/ slight texturing, NO SPRAY PAINT!
  • Masked engravings to prevent texturing grit from obstructing markings
  • No rough edges or internal blemishing, bolt will slide perfectly, just like factory
  • No cracking, splitting or other weld failures, guaranteed ( 100% track record to date )
  • No rushed work/assembly line procedures or “unskilled help”
  • Hours of special attention to detail will be spent on YOUR project…



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