AR57: Fun Times with a Tiny Carbine (aka FSS Hurricane)

Thanks to MagPul for sponsoring this video! I was happy to use one of their new Daka Grid rifle cases today – it’s a very cool system that will be of great use for me both because of its modular configurability and its excellent security.

The AR-57 is a system developed by Rhineland Arms in the early 2000s which uses the FN P90 magazine (and its 5.7x28mm cartridge) in an AR upper. The magazine mounts on top of the barrel, and it ejects downward through what would normally be the AR magazine well. Any standard AR lower can be used, although the company (AR57; a separate firm spun off for this product) sold complete guns using OEM receivers form Aero Precision.

The uppers were made in three barrel lengths, and I have here an example of a first generation full-length rifle and a second generation SBR with a 6.25″ barrel and a GSL Technology suppressor nested inside the handguard.

Further thanks to Battlestar Gatlactica for the loan of the 1st generation rifle!


  1. President Lyndon B Johnson liked serial numbers. I do not. So thus follows the exposition of the Lyndon, one of which you can see at the bottom of this picture:×545.jpeg

    Take one AR-57 upper & buffer (weight), one AR trigger jig, one KE Arms KP-15 pivot pin, one AR FCG, one AR buffer tube and spring, and an AR thumbhole stock. Assemble. You now have one floppy A-57 rifle (the R is missing), but the reciprocating bolt will force all the parts into alignment when necessary.

    If necessary, a red dot sight can be mounted on the forward Pic rail, leaving room for a flip off magnifier on the rear rail.

  2. What kinda bums, at 12:00 you can see a hammer in KP-15 with a significant flat area, quite unlike a mil-spec hammer. If the firing pin in the bolt were routed diagonally and came out at the very top of the bolt, this sort of arrangement would serve as a degree of OOB safety. Many guns work like that, for example Ruger PC Carbine. It works the best if the hammer axis is close to the bolt and the hammer is short.

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