The USC is the bastard child of HKs modern long gun line. It’s comically long, the stock is corny, and the mags are limited to 10 rounds. In order to get it to ‘true’ UMP status you’re looking at a grand total of at least $3000-3800 in gun/parts/labor. And to be honest it’s not even that great of a gun even when it’s done.
But it’s an icon of my gun-loving childhood and I still felt the itch. So with that said, here’s how I took an otherwise homely USC and got it a hell of a lot closer to the gun it was intended to be.
1) Buy the USC, they can be had as cheap as $1150-1299 on various sites/Gunbroker. Let’s face it, they ain’t fast sellers
2) SBR it. Eform1 turnaround times are in the teens-of-days and it’s super easy. $200.
3) Chop the barrel. I opted to have it threaded, which costs a little more($150), but the extra budget minded could have a basic cut/crown for $50. Shout out to Andrew at Atwell Tactical who did mine. And my PS90 SBR.
4) Buy some rails for the top and sides, they can be found for anywhere from $50-100 for the set if you browse HK classifieds here and there.
5) Buy some 15 round mags to supplement the factory 10s. They’re ProMag (I know..) but they’re 100 percent reliable over 500+ rounds so far. If there’s anyone who could screw up a single stack direct blowback mag it’s ProMag, but I don’t know what to tell you, these work.
6) Here’s the part that sucks the most, but highly worth the effort if you’re even halfway handy. I used a hacksaw to cut through the lower spine of the stock, a dremel to carve away the inside ‘bridge’ of the stock, and a heat gun to reshape the bottom spine up into a more UMPy position. A couple of subtle screws to hold it in place and some JBPlasticweld later and it looks about a thousand times better than the original thumbhole abortion. Cost $8 and about 2 hours time.
So for about $1650 (including the tax stamp) I’ve got myself a “poor man’s” UMP. It’s fairly accurate, the trigger sucks big time, and the recoil is disproportionately heavy compared to the round it fires, but it’s also supremely reliable and cool as hell. Which basically sums up every HK currently made.
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