SIG SAUER 551 5.56x45mm

Widely regarded as one of the finest battle rifles in…

Widely regarded as one of the finest battle rifles in the world, the Sig Sauer 551—shown here with two coupled magazines, folding stock fixed, and Trijicon RCO ACOG mounted—is a sterling example of Swiss craftsmanship.

While the Swiss are renowned for high-quality watches, that same precision and craftsmanship goes into their high quality rifles and pistols. Switzerland’s army is primarily a citizen force that relies on reservists to go into battle on short notice if needed. As a result, Swiss reserve troops historically take home their rifles and enough ammunition to fight to their rallying point. In the mountainous terrain of Switzerland, thousands of well-trained riflemen can make advance difficult for even the largest and best-trained army. Therefore, to keep those Swiss riflemen well-trained, shooting competitions and practices are common—to the extent that major highways are sometimes closed on Sundays to allow long-range shooting across them.

To shoot precisely it is necessary to have a precision rifle, and the Swiss do in the Stgw 90, their current service rifle. Chambered for the Swiss version of the 5.56x45mm NATO round, the Stgw is considered by many, myself included, to be the best battle rifle in the world. The Stgw 90 was adopted in 1990, as its name implies. But I was fortunate enough to shoot the Sig 541, upon which the Stgw 90 was based, a few years earlier when the Swiss Grenadier Paratroops were evaluating it. I’ve been a fan ever since.

sig-sauer-551-556x45mm-bThe gas value on the Sig is on the more open setting and this view shows how close to the receiver a coupled magazine rides.

Stgw 90 Details
The Stgw 90 uses a long-stroke gas piston of the type currently in vogue, along with a rotary bolt. In many ways, the system is similar to that of the AK-47. But unlike a conscript infantry, for whom the AK-47 was developed, Swiss reservists are well trained and steadfastly maintain their rifles. Nevertheless, the Stgw 90 will keep running even when dirty. Another feature that makes the Stgw 90 such an excellent weapon is its superior ergonomics. Its ambidextrous selector/safety switch is well located and large enough for ease of operation, even in gloves. When locked open, the folding stock is as comfortable and solid as the fixed stock on most rifles, and the pistol grip is extremely comfortable. A bolt hold-open is easily released after a magazine change by operating the bolt catch lever or using the bolt handle. I also find the lever magazine release easy to operate with either hand. Another plus is the well-shaped and comfortable polymer handguard. Accuracy is enhanced by the 20.8-inch cold hammer-forged barrel, which in original Swiss military format had a 1-in-10-inch twist, although later 1-in-7-inch barrels were produced to stabilize heavier SS109 ammunition. Standard sights are a front post and a rear rotating diopter drum. The combo offers the best iron sights I’ve used on a standard battle rifle.

sig-sauer-551-556x45mm-cControls on the Sig 551—selector/safety, adjustable trigger, and paddle mag release—are all readily accessible to the operator.

Load Comments
  • SANDMAN

    550 & 551-A-1 BEST 6.56X45 RIFEL DESIGN MADE IN THE WORLD!!! IT’S TO BAD USA DID NOT ADOPT THIS FOR SERVICE WEAPON. THEY NEVER LEARN SIMPLICITY IS BEST! JUST LOOK AT AK 47, SVD-S(TIGER) , FN-FAL, M1GRAND,&SKS. THE RIFELS LISTED ..
    ARE VERY SIMPLE & HAVE VERY FIEW MOVING PART’S & FUNCTION VERY WELL. BY THE WAY ALL YOU NEED TO SERVICE THEM IS A S HOE LACE WITH KNOT’S IN IT & SOME OIL ON IT AN PULL IT THROUGH THE BARREL AN IT’S GOOD TO GO !! THAT WHY THEY CUTTING USED & SURPLAS RECIEVERS IN HALF!! LOOK THE MAW WE ARE STILL USING IT!! I HAVE A SIG 551-A-1 R & OTHER LISTED.. I USE MY SIG 551-A-1 IN RAIN,WATER,MUD,DIRT& BRUSH .HUNTING WILD HOGS. IT WORK’S EVER TIME & CAN’T STOP IT! !!! YOU OR CAN’T GIVE or GET ME TO USE A AR,M4,15,16 IT TO HIGH MAINTANCE!!!!.. P.S. THE ONLY THING BAD ABOUT SIG SAUR THEY THINK THEY ARE THE ONLY ONES THAT CAN WORK ON GUNS & DON’T WANT TO SELL PART’S TO PUBLIC AND IF YOU BELIVE ME CALL THEM & TRY TO BUY A QUAD RAIL FOR A 551-A-1 RIFEL & LONGER BARREL.. THE PERSON I TALKED TO WAS A REAL ANAL BUT WHOLE !!!. I HOPE THE REST OF SIG SAUR EMPLOYES ARE NOT MODLED AFTER HIM. MOST CO. LOVE SELL PARTS TO PUBLIC…….. SANDMAN ARMORER………..

  • kriskros

    well, u can have an AR15 all you want; i still get frequent shots in the 4-inches at a distance of 331yrds with my 550; try that with any other AR. oh, and i still do it after having fired around 15’000 rounds while i was in the service. its a great tool!

  • Chris

    As a prior owner of 556 SWAT I am entitled to voice my opinion. The mag release could get stuck when pressed and and the fire selector was rather stiff. The charging handle also obscured any optics I tried to mount. Not only that, it was particularly nose heavy (even without the quad rail). I solved all these issues when I sold it towards an AR. Be a proud owner of one all you want, I am proud to be free of mine.

  • Matt

    Chris,
    You obviously don’t understand the concept of giving the people what they want. The 55X series rifles were banned here and since AR15 STANAG mags are everywhere here in the USA, it was common sense to go with the 556 platform. Rock and Lock AK style mags are not only unpopular because of familiarity with the AR but much more expensive and harder to speed reload. Don’t hate on what you don’t understand. I am the proud owner of a 556. I would take it over an AR all day and twice on Sunday.

  • Chris

    This should have been what Sig released here in the States instead of that, AR15-ified 556. If I want features of an AR15 I’ll just buy an AR15.

  • Richard

    Swiss have alls supple there army with best firearms they could fight this being one of many of them.