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

Hrachya H
by Hrachya H

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 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
Hrachya H

Managing Editor Being a lifelong firearms enthusiast, Hrachya always enjoys studying the history and design of guns and ammunition. Should you need to contact him, feel free to shoot him a message at

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