Hi, all! I just picked up a 556 SCM on a 'whim'. I have been pondering a piston-driven rifle of tactical heritage for some time now. I have been shooting AR-15's for a loooong time, and as the new(?) piston-driven variants and conversion kits began to become vogue, I pondered buying one. However, something about a piston-driven AR-15 didn't quite sit right with me (I'm too old-school, I guess). Then I laid eyes on the 556, and I had a good feeling about it since it was designed from the start to be piston-driven. Also, I could utilize the countless AR magazines I have, as well as the ammo. I began researching the 556 further and that's how I located this site. My perusing of the forums thus far has been quite a dizzying array of (positive and negative) opinions, comments, criticism's, and complaints. Excellent! What better an atmosphere to 'learn or burn'? I'm a relative newbie to SIG's rifles, but not SIG in general. I do own a P226 that I absolutely love, and am looking to add another to my collection soon. So begins my journey into the realm of the 556! I'm glad I could join you all! Happy and safe shooting! Best!