So I've been fooling around with different spots and I think I've narrowed it down to mounting the RSA about 1-2 inches from the receiver on the hand guard. However I can't decide whether to put it on the left rail facing upwards or on the top rail with it facing to the left. Just curious how you have your rigs set up. BTW its on a 10" MI rail with 14.5" barrel. I also have the magpul ASAP and MS3.