Swiss Arms/Sig 55X Rifle Series Explained

Due to import restrictions, the Sig 55X rifle series is pretty rare in the United States. As a result, many Americans are unfamiliar with this excellent weapons system, while others around the world are intimately familiar with it. Rico Ghinolfi was the Swiss Arms gunsmith pulling IWA duty, and he took a lot of his time to discuss this and other topics with me. He’s a very knowledgeable and skilled individual, and I learned a lot from our talks – I tried to stop by every day and pester him with more questions, none of which he had difficulty answering.

It was not my intention for this video to go in depth, but it should give the average firearm fan who is not familiar with the platform a good understanding of its features – and the differences between the various models.

Sig 55X Rifle Series

Andrew Tuohy

Andrew Tuohy was a Navy Corpsman with the 5th Marine Regiment. He makes a living by producing written and visual content within the firearm industry, and he also teaches carbine courses. He prefers elegant weapons for a more civilized age, and regularly posts at Vuurwapen Blog.


  • SpudGun

    Had an opportunity to shoot a 550 many years ago and really, really liked it. Haven’t tried any of the Sig USA efforts and finding a general consensus on the merits or detractions of the 556 / 516 seems to be pretty difficult.

    That 553 is pure sex though.

  • Jesse

    That last rifle is awesome with the 4 position gas system. Amazing technology.

    Watching these videos you’ve been doing with the various European companies it reminds me of the two times I’ve been to Europe and both times every single person I ran into would apologize to me for not speaking better English when in reality their English was damn near flawless.

  • Don

    Who knew Buster Keaton was a Swiss Arms/Sig rep? That’s so cool!


  • Lance

    Decent weapons I do like the 551.

  • JonMac

    300m with that barrel? Really?

  • Matt

    Awesome post! I am a huge SIG fan and the proud owner of a 556ER with Swiss internals. My rifle has been flawless despite people ripping on it (mostly AR fanboys). I would love a SIG 751 SAPR or a PE90 from Cananda. Hopefully someday, if we can get rid of some of these stupid import laws, we can order direct from SIG Europe.

  • That second rifle did not look much shorter than the first. Hardly an entry or CBQ carbine.

  • Andrew (European Correspondent)

    JonMac, yes, the weapon is capable of placing rounds accurately to at least 300m.

    Federale, the Sig 551 has a 14.3″ barrel as opposed to the nearly 21″ barrel of the 550.

  • Andrew (European Correspondent)

    Correction/addition to my above comment. The 551 SB has a 14.3″ barrel, the 551 LB has a 17.8″ barrel.

  • Andrew (European Correspondent)

    Ack, one more addition. The models on display were intended for the German civil market and therefore do not correspond exactly to the “military” versions of the same weapon. We worked with what we had.

  • snmp

    for explanation of that’s pepole of Sauer

    * FASS 90 /STGW 90 Military name of SG550-1
    => FASS 90 /STGW 90 “P” (Military version with out Full auto mechanisme),
    => PE90 (Privat Einzelschuss) civilian version with lower incompatbile with the uper of the FASS90
    – SG550-1(= Fass90) with twist 1- 10″ (GP90 amunition)
    – SG550-2 twist 1- 7″

    * FASS 04/STGW 04 Military name of SG-552-1 (with twist 1- 10″ ) & the SG552 have not the same mechanism than the FASS90 & SG551.

    * FASS 07/STGW07 Miltary name of SG553-1 LB

  • Marty

    I am Canadian and am very lucky to have a semi-auto SIG 552 8.9″ barrelled CQB rifle. These are incredible rifles and a lot of us in Canada take advantage of being able to buy these realizing its one of the only firearms that American’s don’t have access to. Its a world away from the garbage that SIG USA is peddling as a 556, however the new price is approx $3200!!!!! That buys a lot of AR’s! Still, I’m very pleased with mine.

    Regards, Marty.

  • Paul

    I’m curious as to what exactly defines the Sig 556 as garbage? I’ve never had a problem with mine. I’ve heard they have also fired 40,000 rounds without cleaning or a single hiccup.

  • Matt G.

    Never seen or handled one of those but they do look very sexy.

    Hopefully one of these days the entire BATFe staff will accidentally fall off a cliff and we normal civilians will be able to purchase these.