Click here to watch a video of the SIG Sauer SIG556xi gun test!

Fresh on the heels of introducing the striker-fired P320 pistol (Click here to watch a gun test video), Sig Sauer has released its new SIG556xi rifle. The latest evolution of the piston-driven SIG556 platform, the SIG556xi brings the modularity of the P320 to the law enforcement and self-defense carbine. It may be the most modular carbine introduced to date. Not only can you change barrels and calibers, but you can also swap out lower receiver assemblies. The upper receiver itself is serialized, not the lower, so you can swap the mil-spec “Standard” AR lower receiver to the “Russian” AK-magazine-compatible lower.

But the modularity doesn’t stop there. Forends can be swapped between the polymer Magpul MOE, an aluminum tri-rail model and a carbon-fiber version. For stocks, operators can choose between a telescoping AR-style stock, the proven folding stock of the SIG556 line and a pistol-style assembly.

With the same upper receiver, you can go from 5.56mm NATO to 300 AAC Blackout (300 BLK) with a simple barrel and bolt change. If you want to fire 7.62x39mm ammo with the SIG556xi, you simply swap out the barrel, bolt and lower. The platform’s controls are ambidextrous, with the safety and mag release present on both sides, and the charging handle can be moved to either side with ease.

Coming straight from the factory with a fantastic set of flip-up front and rear iron sights, a quality sling and a mil-spec magazine, the SIG556xi is ready for work right out of the box. Coupled with the new Sig Sauer P320 pistol, you have a dynamic duo of modular weapons that is perfectly suited to the police armory. Take a look at my video to see the new SIG556xi in action, and look for a full report in the upcoming September 2014 issue of GUNS & WEAPONS FOR LAW ENFORCEMENT. To subscribe, visit

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