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Welcome, SIG Addicts your daily fix for all things Sig Sauer

Pictured is the "Russian" variant of the new SIG 556xi. Although you may have seen this rifle listed on Sig Sauer's website, you haven't heard half the story.

The SIG 556xi - a piston-operated rifle with three valve positions - will be replacing all of the previous SIG 556 variants on the commercial market. Why? Because the SIG 556xi is a modular rifle. It will be offered in three popular calibers, and three of the four new models will be able to swap calibers on the fly.

This places the SIG 556xi on the same table as the SIG MPX and the SIG MCX, in terms of modularity. Makes you wonder what else Sig may have up their sleeve this year...

Click "Read More" for all the details! (Update: more pictures added)

The SIG 556xi will be shipped with fully featured flip-down sights, either of two side-folding stocks or an AR-style stock, and a new, three-prong flash suppressor.

The safety lever and mag release are ambidextrous, and the charging handle can be swapped from one side to the other.

The barrel is removable and will be offered in three lengths: 16", 14.5", and 10".

In addition to the "Russian" variant (which will be available in 7.62x39mm only), there will be three models - all of which can be field fitted to fire 5.56x45mm NATO, 7.62x39mm Russian, and .300 BLK ("Blackout").

Like the MCX and MPX, the user can simply swap the barrel and the bolt, and it's ready to accept the appropriate magazine! And speaking of mags: the caliber-swapping variants will all accept AK mags, Stanag mags, and AR mags.

Finally: all of the upper receivers will be compatible with the lower receivers of the SIG 556 rifles that they are replacing.


Here are the new model names and basic retail descriptions:

SIG 556xi - standard model, comes with standard side-folding stock (with removable cheek pad)

SIG 556xi Carbon - enhanced model, comes with carbon fiber quad rail, and skeletonized side-folding stock

SIG 556xi Russian - similar to standard model but chambered in 7.62x39mm Russian only, comes with standard side-folding stock (with removable cheek pad)

SIG P556xi - pistol model, comes with quad rail and SB15 forearm brace

This is an incredibly exciting year for Sig Sauer fans! Be sure to keep watching SIG Addict for updates. Hopefully we'll get our hands on these rifles next Monday.

And remember: you saw it here first!

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Posted: 2 years 3 months ago by jlbe #7679
jlbe's Avatar
Thanks TX, this is an intriguing development. The upper/lower receiver compatibility is particularly interesting.

I look forward to your hands on assessment. J

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