Since the Sig 556 is available in the USA now, I decided to start this thread (Sig is doing what HK SHOULD be doing, namely building rifles in the USA to avoid daddy Bush's/Klinton's import bans). I don't have a Sig 556 but I saw one at the last gun show and a local gun store has one.
Click here for XCR info
Click here for SIG 556 info ***** Click here to go to Sig's webpage for their 556
Click here for M96 info
Click here for AR 180 info ***** Click here for information SPECIFIC to the AR-180 B which is currently being manufactured by Armalite.