I'll second MedicMan's opinion - the Sig 556 is a pretty solid choice and is consistently on the low end of the price range for "AR-like" piston guns. I've had one for 3 years or so now, and I'm pretty happy with it. I don't shoot 3-gun matches (though I'd like to at some point), but I think that the 556 would work well for that application.Monker10 wrote:Yep I am pretty set on a piston.
I think that most of the complaints about the Sig 556 among the internet tacti-cool crowd stem from the fact that it's not an AR. Professional reviews that I read before buying mine (which, even taken with the grain of salt that they're probably brought to you in part by Sig-Sauer, I trust more than random internet yahoos) don't mention significant problems, and I certainly haven't discovered any.