Sig Sauer Guns have confirmation that the SIG556 (the civilian SIG550) will be made available chambered in 7.62x39mm and will be able to use standard AK-47 magazines.
We just received a phone call from our contact at Sig and Sig Sauer is producing a SIG 556 chambered in 7.62×39. This new SIG556 will have a AK-47 bolt and it will support standard AK-47 magazines. Apparently these new models are in production and will be shipping from the factory in roughly four to six weeks.
Read more about it here.
This is pretty nifty if you ask me.