New SIG SIG551A1

    SIG Sauer will soon be shipping the SIG 551-A1. This rifle is essentially a SIG556 upper receiver, with Swiss-style furniture, combined with an aluminum SIG 551-style lower receiver. The biggest difference between the SIG 551A1 and the SIG 556 is that the former uses Swiss transparent polymer magazines instead of AR-15 magazines.

    TACTICAL PRECISION, For 2011, SIG SAUER® is offering several variants to its tactical platforms. NEW to this lineup is our new SIG551-A1, chambered for the widely used 5.56 x 45mm NATO caliber using Swiss Polymer magazines. The SIG551-A1 features a distinctive swiss folding stock, and an M1913 rail for accessory attachment. The 16” barrel features four-groove rifling and a twist rate of 1:7”. The SIG551-A1 measures 36.1” but can fold to 26”, making it ideal for situations where maximum maneuverability is required. For Special Forces requiring an accurate, more potent rifle, chambered in 5.56 x 45mm NATO, the SIG551-A1 sets a new standard for dependable operation and function.

    This rifle will mainly appeal to law enforcement or consumers, who would rather use the Swiss transparent polymer magazines instead of standard AR-15 magazines, and collectors.

    Caliber 5.56X45mm NATO
    Overall Length 36.1”
    Length with Stock Collapsed 34.6”
    Length with Stock Folded 26.0”
    Barrel Length Without Flash Suppressor 16”
    Operating System Gas piston, rotating bolt
    Rifling Lead 1 in 7”
    Number of Grooves 4
    Muzzle Brake Fluted
    Sight Radius 18.0”
    Weight without Magazine 7.0 lbs
    Magazine Type Swiss Polymer
    Magazine Capacity 20/30
    Trigger 2-Stage
    Trigger Pull 7.5 lbs

    NRA’s American Rifleman staff took the SIG 551A1 out to the range …

    Steve Johnson

    I founded TFB in 2007 and over 10 years worked tirelessly, with the help of my team, to build it up into the largest gun blog online. I retired as Editor in Chief in 2017. During my decade at TFB I was fortunate to work with the most amazing talented writers and genuinely good people!