I am building an A1 superlight barreled upper .... I had decided on the Olympic barrel for accuracy, but then I thought, this is more of a utility rifle.... maybe I should use a bushmaster chrome lined superlight barrel?  Are the Bushmaster chrome lined barrels quite accurate? Doesnt Bushmaster use slightly looser chambers for more reliability?

First off you're looking to build a carbine with a lightweight barrel.

Do you really expect 'tack driving' accuracy?  Do you really need tack driving accuracy?

If you NEED the accuracy then look to a heavy match barrel in stainless (Oly has some reasonably priced SUM barrels).

Otherwise the Bushmaster chrome lined superlight is what you want.  It is plenty accurate, and I seriously doubt if you are a good enough shooter to notice the accuracy difference between a chrome lined Bushy and the unlined OLY (no flame but a statement of fact).

Yes the Bushmaster will be more reliable.