Just about all the 7.62x51 NATO surlpus has been shot, sold or destroyed by now. That said, there seems to be quite a bit of cheap Norinco 7.62x51 on the market at the moment. Haven't seen prices this low in at least 5 years. That said, why not reload? There's still plenty of brass around.
once they get done with the 2 wars in the middle east you boys might see a good influx of surplus 7.62x51 in a couple years time