Max.. I've shot a bit of 3 gun using the AR platform... don't have a Sig, but my cousin does, and I shot his... pretty much a standard AR.. forged 7075 receiver with the MagPul furniture... his shoots 1 1/2" or better at 100y...if you are looking for opinions for a competition rifle, I'd suggest a full float forend, mid length gas system, and a better trigger, but with the Sig name, you should be good to go for targets out to 200m or so...