What are you looking for in a semi auto 7.62 ? The M1A will run a long time w/o cleaning. I've got a Squad Scout model that has run about 400 rds. w/o any more cleaning than the removal of the factory bore oil. While it has shot a few groups under MOA, for three rounds, most of the better loads run 1.3 to almost 2 MOA for four rounds. None of my loads use any match bullets, BTW.
The only M1A models really setup for scope use are the latest Loaded models with the fully adjustable stocks, unless you would be happy with a scout scope on the Socom or Squad Scout.
Some of them, like the Loaded version with the fully adjustable stock are reported to run 11.2 lbs. w/o a scope.
My Squad Scout runs 8 lbs. 11 ozs. with the Leupold VX2, 1.5-4X Scout Scope.
If you insist on something lighter, on an AR style design that will readily take a conventional scope, I hear alot of good things about the S&W M&P 10.
While it can argued that the AR style 7.62's can't run as long and hard as the M1A's or the FNFAL, they do alot better than Remington 750's or the other sporter style semi auto .308's.
I talked to alot of people about the Smith M&P 10 before I bought my M1A Scout. I bought the Springfield basically because it handles better for me than an AR style rifle would.
That and I don't need a more powerful scope than the 1.5-4X Scout for what intend to hunt with it.
But both rifles have a rep of running alot longer or harder than the Remington 750 or the Browning BAR. They work under dusty, dirty conditions where the above don't.
Mine doesn't change zero when hot. I understand the Smith M&P 10 doesn't either. Both of them don't recoil off target much thanks to their designs.
The M1A's come with really good triggers and excellent, well protected iron sights. The Smith M&P needs a quality after market trigger to make me happy and has to have irons added.
So, do you really need/want a rifle that can run hot for hundreds of rounds under bad conditions ? Or will something not quite to that level of performance make you happy.
BTW, the M1A Loaded, National Match and Super Match rifles have the reputation of not being 100% reliable when shooting some mil surp ball ammo. Something else to consider. E