SAI CSR-50: Compact .50 BMG Rifle made in Denmark

CSR-50 is a very compact single-shot bolt action anti-materiel rifle chambered in .50 BMG. It is manufactured by a Danish company called SAI (Small Arms Industries). It is actually a bullpup rifle, which manages to fit a 28.4″ (720 mm) barrel in an overall length of 38.6″ (980 mm). The rifle is also very lightweight weighing less than 22 lbs (9.8 kg).


The bolt of the rifle is mounted on its stock. In order to work the action, the operator must lift the bolt handle and pull the stock rearward, then insert a cartridge into the chamber, push the stock back and rotate down the bolt handle. The bolt/stock assembly runs on a couple of guide rods mounted on either side of the receiver. Perhaps this is not the most convenient mechanism, but that’s the tradeoff of the super compact size. You can watch how the action works in the video below:

Judging from the video, it seems that the rifle lacks an ejector.

CSR-50 features a Lothar-Walther match grade barrel and all steel construction. The rifle’s parts also have a rather unusual surface finish called Corr-I-Dur. It is a multi-layer thermochemical treatment, which works both as an anti-corrosive finish and a wear resistant. That finishing process is developed by a company called Bodycote. More information about Corr-I-Dur finish is available on Bodycote’s website, which you can read by clicking here.

CSR-50 (4)

CSR-50 also features a top Picatinny rail, a bipod and a massive muzzle brake.

Of course working the action looks to be a pretty awkward process and the single round capacity is also a drawback. However, it can be a rifle of choice if the size and weight are the most important characteristics for a certain application. After all, it is a .50 BMG rifle with a sufficiently long barrel and an overall length of an assault rifle.

Hrachya H

Being a lifelong firearms enthusiast, Hrachya always enjoys studying design, technology and history of guns and ammunition. His knowledge of Russian allows him to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience.
Should you need to contact him, feel free to shoot him a message at


  • DW

    Serbu, this is what you should have made.

    • RSG

      I came to the comments to post something similar. The finest BUDGET 50 in the world.

  • Giolli Joker

    I like it!

  • Gary Kirk
    • Giolli Joker

      Wasn’t the butt stock coming off completely there?
      Similar concept indeed, however.

    • A bearded being from beyond ti

      Perfect for tranquing dinosaurs.

    • Mr. C

      To be fair, the SAI seems like a superior design. 8 inches shorter and 8 pounds lighter is nothing to scoff at.

      • PK

        That seems to mostly be the barrel length and barrel weight, honestly. Shellholder rifles are all incredibly light and short, as they’re remarkably simple mechanisms.

    • PK

      Or the Maadi, or many other shellholder design .50 rifles.

    • singlestack

      Favored by Graboid hunters everywhere. Just ask Bert.

      • Tierlieb

        It might overpenetrate, though. But how was he supposed to know? After all, he was denied critical, need-to-know information.

  • A bearded being from beyond ti

    Are these legal to own in Denmark?

  • DanGoodShot

    Yeah, may be a bit awkward at first, but it looks as though its something that you could get used to rather quickly. Me like. Me want.

  • Emfourty Gasmask

    that has got to suck to shoot with a suppressor

    • Xtorin O’hern

      why? its a bolt gun not a semi auto

      • FarmerB

        No brake.

        • Xtorin O’hern

          you know suppressors reduce recoil almost as much as a brake right?

          • FarmerB

            I know a lot of people say that (many who have probably never done it), but in my experience it’s not true. It might make it more pleasant to shoot from the point of view of blast, but it recoils more.

          • Xtorin O’hern

            they really do, i have never done it one a .50 but i have done it on multiple smaller calibers and it really does reduce recoil. i cannot comfortably shoot my buddies .300WM without his suppressor and it’s certainly not the blast as my hunting rifle of choice is a 16 inch .308 with a muzzle brake

          • FarmerB

            Yeah, I know people say that, especially with smaller calibres. But I think they are confusing the general pleasantness of shooting it with the actual recoil (it can be hard to separate the two unless you concentrate on it). The .338’s I shoot are much more pleasant to shoot with suppressor (which I do quite a bit), but if you concentrate on the recoil – there’s more of it there. But with a .50 to me it’s very clear: when it’s my trigger time on the 50, I know it’s going to hurt when suppressed (and you have to be even more careful that the scope doesn’t kiss you).

            Next time you’re on a big gun (>.338) try to test it out – I’ve made the comparison many times. You don’t have to agree, but the story that suppressed firearms don’t have as much recoil isn’t clear cut, and I maintain fundamentally wrong.

          • Dan

            I found it was about an even trade off. A little more recoil for not having brain rattled by muzzle blast. I only fired a few dozen rounds from a suppressed .50 though. Maybe that trade off goes away after awhile

          • Rocketman

            Not true in my experience either or at least not much. The HK-91 that I shot had a suppressor on that at most a 5 or 10% reduction in recoil compared to one that didn’t have it on if even that. And it wouldn’t even swear that there was any reduction at all. I just might have been expecting some and imagined it.

          • FarmerB

            Remember, we’re talking here about large caliber rifles with a brake on versus suppressor (no brake). If you put a suppressor on a rifle that has no brake, then maybe it’s closer in felt recoil. In fact, a significant component of recoil is the gas shooting forward from the barrel, which the suppressor will somewhat mitigate. But you have no brake, so all that blast increases recoil rather than help decrease it. I’d still expect a semi-auto to recoil more with a suppressor, because it’s now basically over gassed – and blowback and roller locked actions in particular to deliver more recoil.

  • Dave Webster

    This is terrific, how much?

  • onehalfheffer

    One angry shot, for Furiosa.