Sent rifle back to Sig for sight alignment and zero issues, called to check on progress only to find out they are sending me a new rifle. My rifle was the Sig 556 with AR collapsible style stock, non folding. My concern is what will the differences be between the one I had and the new one they send other than serial #'s, I asked the C.S.R some of the same questions and all he could tell me was it wouldn't be the same style rifle. So does anyone have any info or knowledge as to differences btween old and new style and is one better than the other; is the cause for the style change? Any info on this would be appreciated on this subject, for now have to wait and see what they send me in return, hope its not a long wait.