I've yet to see an AR weigh on my scales at 5.5 lbs but my scales may be off too. The lightest one I've seen was a 14.5" pencil barrel and it was 5.9.
My LW uses Rainier Arms upper without a forward assist, Colt pencil barrel and a shaved gas block. A shorter Troy Alpha rail would cut down some weight as would a standard carbine buffer and a semi bolt carrier or get radical with a JP system. Makes me want to try again and build another...
I must resist!
