Sighting in ACOG with .223?

Ok, last question about ACOGs. I'm going to the range tomorrow and I am going to be sighting in my TA33G-8 : 3x30. I have a 16 inch bushmaster M4 type carbine. I was wondering if I could sight it in at 100 yards instead of about 109 yards (100 meters). Also, should I bore sight it first? And with a 65 grain .223 will I have a straight shot? What I mean is, when the round leaves the bore, will it rise up and then go back down before it hits the target? And should I pay attention to how many clicks I adjust it or can I just adjust until it's zeroed? Thanks!