the acog is a GREAT battle sight! they are acually designed to be shot with both eyes open (faster target pick up). i think its called the bindon? aiming system. every marine in a combat unit has one, the shooting with both eyes open takes a little getting use to, but once you get the hang of it you'll wish you would have started sooner! they hold zero's very well (never lost mine, even in a car bomb at 30'), i guess if they have a down side is that in a house/CQB, the magnification can screw with you a bit. what we trained to do is what is called indexing... you lay one of your fingers down the line of your barrel, and you just point your finger at your target and squeeze the trigger. it's very simple and very effective after very little practice. it will become muscle memory!