You used the words "accurate" and "semi-auto" in the same sentence...
If you want accuracy, don't get hung up on tacticool semi-autos. You can buy a -fair- semi-auto for that money. Or you can buy a pretty decent bolt-action, that'll likely shoot a LOT better.
Do you want accuracy, or do you want a big magazine? Remember - if you want to KEEP accuracy, you're not gonna want to overheat your barrel, and you're going to want to clean it frequently.