TFB Review: The HK USC Carbine

Welcome back to another TFB Review. A couple of months ago I decided to jump in and take a look at the HK USC which many have converted over time to the well-known UMP series that we are unable to get from HK as a standard option. Just like many like to convert the SL8 rifle into the G36 line of rifles. Of course, certain companies out there offer conversions on the USC and SL8 firearms but they can be fairly expensive with long lead times depending on the models. My plan is to look at the USC as a rifle and then eventually convert it into the classic UMP we all know and can appreciate. The first thing we have to do though is look at how the base USC rifle does on its own. Let's take a closer look at the HK USC Carbine.

HK decided to drill and tap the USC for Picatinny rails on the top as well as the handguard section although they do not include it with the firearm. The trigger on the standard USC is a crisp single stage with an audible reset with little travel to reset. One of the last things to talk about is the one-piece stock that resembles the thumbhole stocks from the 90s that were fairly popular on imported AKs. The sights are fixed in the front with an adjustable rear that can be adjusted for windage and elevation. Each USC comes with a soft shell case, a little tool kit, and two magazines as standard. MSRP on the USC is $1,749.99 and it is available now from all major retailers.

Range Time

I have had the USC in its factory configuration for roughly two months and even though it’s not exactly tactical, it still is enjoyable to shoot. Despite being a longer 16” barreled rifle, the USC is incredibly lightweight which makes it easy to shoot quickly with the ability to quickly snap between targets. During the last couple of months, I put roughly 550 rounds through the gun mostly consisting of Federal American Eagle 230gr ammunition. The 10-round magazine isn’t massive but the enlarged thumb release makes reloads effortless with a slightly flared magwell helping as well. One thing that really took me by surprise was how crisp the trigger was for being an HK trigger pack. This had a very defined wall with a crisp break and short reset. As a factory trigger, it's one of the better PCC triggers I have felt from HK.

The iron sights are very basic but do the trick. If you have ever used a C7 style AR15 or any of the fixed sight A1 variants, the iron sights are similar to those older style iron sights. HK incorporated the classic forward cocking lever just like the MP5 style of firearms which also allows you to do the classic HK Slap when you reload from an empty magazine which gives you extra style points. The recoil on this lightweight polymer PCC is a bit snappy in 45 ACP which surprised me coming from shooting countless MP5 variants. It’s not a deal breaker by any means but if you shoot a lot of MP5s, you may be surprised at the slightly snappier recoil the USC has.

Accuracy and Reliability 

For accuracy testing, I used a few different rounds. The majority of my shooting was done with 230gr Federal American Eagle with a few of the 230gr HST defense rounds as well as some Hornady 185 FTX Critical Defense rounds. For each test, I shot groups of 5 rounds at 30 yards with the gun being in a gun rest to try and take out as many variables as possible. With the American Eagle 230gr rounds, my average group out of a 5-shot group was 1.46”. With the HST defense rounds, it was 1.29” and the Hornady FTX rounds 5-shot group was 1.33".

In terms of reliability, I only put 550 rounds through the gun, but everything was 100% reliable. The earlier generations of the USC were known to have occasional feeding issues and if you go online, oftentimes you will see people discussing that, but my example that I picked up from Brownells was completely reliable with all the ammunition I put through it. I like to make it clear that I bought this from Brownells rather than ask HK for a T&E gun to see what one picked out randomly would do and it was fantastic.

Suppressor Options when Converting It

I do plan on converting and making significant changes to my USC to make it a UMP, one of the decisions I have to make is what suppressor should be put on the gun once it has a threaded barrel. I’ll certainly be filing paperwork to make it a legal SBR and depending on how long that takes, it’s important also to purchase your suppressor at the same time so you can get the paperwork and tax stamp information going at the same time. They will either take the same amount of time or the SBR stamp will take slightly longer depending on current backlogs.

The HUXWRX Rad45 suppressor is an interesting choice for a 45 ACP PCC rifle because it can be configured either in its longer configuration, or you can unscrew the extension and run it as a short configuration. This allows you to have a fairly modular can to either focus on suppression or a shorter overall length. In my experience. This suppressor has really good noise suppression and is a lightweight option compared to other products on the market. The rear end can be switched between direct thread or other mounting options. In previous experience, I have used the direct thread option or the Tri Lug adapter with both being great options if you wanted to use it on something like an MP5. Being able to move from a longer or shorter can helpful depending on what you are doing but the full extension installed with 45 ACP makes firing out of a gun very quiet and naturally subsonic.

A classic choice and one that looks a bit more modern compared to other options is the Osprey 45 suppressor from Silencerco. This suppressor is an absolute workhorse and offers the durability and longevity required to live on a PCC indefinitely. Without cleaning, the Osprey 9 has been one of the most durable suppressors I have owned. The piston system does a fantastic job on pistols and with the PCC, it would be the perfect pair for a hard-use PCC or SBR option like a UMP.

Overall Thoughts 

The HK USC has incredible potential to be incredibly user-friendly given enough love, replacement parts, and attention. It is by all means very usable as a firearm right now and with the longer 16” barrel is accurate for a PCC chambered in 45 ACP. I plan on doing a full write-up of when I start converting it to an SBR and turning it into the UMP-style firearm. Be sure to keep an eye out for those articles later down the road.

Let me know what you think in the comments below. If you have questions about the USC or firearms in general, feel free to shoot me a message on Instagram @fridgeoperator. Stay safe out there and keep an eye out for part 2 of this write-up when I start to convert it to a proper UMP.