My SIG 556 has been utterly reliable but accuracy is not as good as my AR 15 platforms. 100 yard 5 shoot groups average 1.5"-2.0". I've tried 52, 53 and 69 grain SMK's as well as hornady 55 and 60 grain spire points. With 4895, 3031, Varget and W748 in half grain increments. The best group I ever shot was 1 moa with 52 grain SMK's and W 748. My AR's (Noveske, LMT, LWRC. SIG 516 and POF) all are sub moa shooters. I haven't shot my SIG 556 in a few years because of it's inferior accuracy.