Defense Review have written an article about the new SIG 556 SWAT Rifle/Carbine/Subcarbine

SIG 556 rifles/carbines at SHOT Show 2006 (photos accompanying this article), and found them interesting. We’ve always been fans of the SIG 550-series weapons, particularly after we test-fired a Gemtech-supressed (sound-suppressed) SIG 552 SBR/Subcarbine at SWAT Round-Up 2002. The SIG 550-series assault rifles / tactical rifles utilize an AKM / Kalashnikov-type gas-piston/op-rod system for operation, and you can’t really go wrong with that with regard to weapon reliability.

While the SIG 556 series weapons are currently only availale in 5.56mm NATO, 6.8x43mm SPC (a.k.a. 6.8mm SPC a.k.a. 6.8 SPC), 7.62x39mm, and possibly even 7.62x39mm NATO (7.62mm NATO)/.308 Win. (unconfirmed/unverified) versions are on the way. DefenseReview doesn’t know at present whether the select-fire variant of the SIG 556 SWAT is available in true semi-auto/full-auto configuration, or only in semi-auto/three-round burst config, or semi-auto/3-round burst/full-auto config. Unfortunately, Mr. Poole’s article does not make that clear. Defense Review prefers a straight semi-auto/full-auto selector switch. We like our trigger finger to determine how many rounds we put down range on full-auto, not an artificial limiter. In any case, the SIG 556’s trigger action in the 3-round-burst-capable variant appears from what Mr. Poole wrote to be superior to the Colt M4 Carbine trigger with regard to smoothness and consistency.

I like their caliber offering. It looks like they will be competing with the Magpul Masada.

More here.