Sig is a huge company that does business worldwide. We are very used to Sig Sauer in the United States, but the Swiss branch of Sig is a little less known.
They produce a variety of weapons for the Swiss military, including the 550 series of rifles.
Americans being Americans means we don’t like when we can’t get things. For the longest time, getting a Sig 550 series rifle simply wasn’t possible — well, kind of. In 2007 Sig announced its intention to bring the 550 series to the American public in the form of the Sig 556 rifles.
Finally, Sig 550 Rifles in America!
Sig released the first 556 to a rather lackluster appeal. The 556 might’ve been a 550 rifle on the inside, but it wasn’t on the outside. Sig attempted to AR-15ize the 556, and people weren’t stoked.
They took away the 550 furniture and replaced it with a non-folding M4 collapsible stock, and the rail system came as steel or polymer that looked nothing like the originals.
They accommodated AR-15 magazines rather than the unobtanium 550 series mags. However, a change that many didn’t mind was the new aluminum lowers.
People weren’t happy with the 556. Not only did they not look like the 550s, but they also had QC issues with canted rails and reliability issues.
Sig then created the Sig 556 Classic, which kept the AR-15 magazine compatibility but with a more classic 550 look. These weren’t truly authentic Sig 550 guns, but dropping the M4 stock and weird handguard in favor of Swiss military look-alikes brought back the distinctive styling of the original.
However, the stocks didn’t mesh well with the iron sights due to their higher position. The front sight got in the way while using optics, and you couldn’t change it. People still weren’t happy.
Will the Real 550 Please Stand Up.
Luckily Sig listened to the consumers, and we got the 551-A1. This new rifle gave 550 seekers a weapon as close as they could get to the real deal.
This included the 550-style furniture with a grey receiver set and authentic 550 mags that rocked into place. The 551-A1 answered the 550 fans’ requests, but many people were soured on Sig USA at this point, and the weapon flopped.
Then Sig did the Sig thing.
Sig is famous for releasing about a dozen different variants of their guns with minor changes. And while the 551-A1 gave fans the 550 they wanted, Sig didn’t seem to produce them for very long.
The Sig 556 became the main game in town. Following it was the precision-oriented Sig DMR, which featured a Magpul PRS stock, a match trigger, and a 21-inch barrel. We also got Sig 556 pistols with 10-inch barrels; sadly, this was in the dark times before pistol braces existed.
We also got the Patrol rifle with a shorter handguard, the SWAT rifle with a Picatinny handguard, and even a SWAT Patrol version with a shorter Picatinny rail.
During this time, Sig produced my favorite 556 variant — the 556R. The R stands for Russian, as it accommodated the 7.62x39mm round and AK-47 series magazines.
Saly, the 556R had immediate issues upon launch. The Gen 1s sucked, and as an owner of the Gen 1, mine was super unreliable with numerous failures to eject. Luckily Sig fixed mine, but they eventually released an improved Gen 2 model to address the problems.
They also released various models like the 556R Hunter, a Sport Configuration Model for ban states, and even offered a 556 Holo that came standard with a red dot sight.
However, the fumbled release of the 556R was considered a major failure, further tarnishing the reputation of the 556 line.
Enter the 556 XI Series
Sig decided to modernize the 556 series with the XI series. They went full bore, adding a new stock with a cheek riser for better sight acquisition, a three-position adjustable gas system instead of two, and an M-LOK rail system to top it off. It was offered in 5.56x45mm and 7.62x39mm, with a .300 Blackout version planned to be released.
They enhanced the ergonomics by making the charging handle reversible for left or right-handed use and featured full ambidextrous controls. Yet, it still suffered from a poor trigger, small aftermarket, and lackluster accuracy compared to the AR-15.
As a bit of a contrarian, I’ve always liked AR alternatives; thus, I’m a big fan of the 55X series. I love my 556R and find it to be all sorts of cool.
However, the Sig 556 suffered poor sales. The rifles were expensive too, and the unreliability of specific models tarnished their reputation. They also didn’t offer any significant advantages over the AR platform and had worse accuracy and downright sub-par triggers.
Sig discontinued the series and seemingly replaced it with their AR variants and their MCX rifle. The 556 now exists as a distant memory in the minds of rifle owners.
Does anyone in the audience have any experience with the Sig 556 series? If so, share it below. Still looking for something different than the AR-15? Check out our article on the best 5.56 rifles that are not AR-15s.