Sig 551A1 announcement
On July 7, Sig Sauer announced the new SIG551A1 carbine:
Based upon the American SIG556 platform, it more closely resembles its Swiss cousin, the Swiss Arms SG551 in a number of ways: magazine/receiver interface, stock, flash suppressor, and finish color. The SIG551A1 lower receiver will accept Swiss magazines, which “rock & lock” into place, similar to Kalashnikov pattern rifles. While arguably a more positive and secure interface, it necessitates a significant change in the weapon’s manual of arms. And, at least for now, Swiss 550-series magazines are significantly more expensive. All previous iterations of the SIG556 series accept STANAG magazines, except the 7.62 x 39mm SIG556R, which uses AK magazines.
The stock returns to the Swiss fixed-length design. This reduces the stock’s complexity in both construction and operation, but also reduces mission adaptability. Having run both types of stocks on the SIG556 Classic SWAT, I can attest that the Swiss stock feels sturdier than the adjustable, but has a very long length of pull for modern tactics. The flash suppressor appears to resemble that of the SG551LB, and the receivers are finished Swiss gray, rather than American black.
No doubt designed to appease those of us who prefer not to reinvent a very good wheel, the SIG551A1 still differs significantly from the SG551. The lower receiver is aluminum, rather than steel, which should make it a bit lighter. Diopter rear and hooded front sights appear to be taken directly from the 556 Classic line. If so, they are cheaper, lacking tritium, and a bit too tall for a solid cheek weld on the Swiss stock (as noted in detail by MFI). Barrel length remains non-NFA at 16″, rather than the 14.3″ barrel of the SG 551, or the 17.9″ of the SG 551 LB.
All these differences should be easily overlooked by the enthusiast on a budget, as the SIG551A1’s street price will no doubt more closely resemble a quality AR-pattern carbine, rather than the CHF3’000+ required to buy an SG 551.