you may consider this a silly newbie question, but i'll ask anyway... and before anyone says it, you try using the search for how to sight in a new AR w,/ a search engine that does not allow for 'and' or 'or' ... ~9 million hits for "irons sights." :)
Anyways, took my new (first) AR to the range tonight... I partly put it together myself (RRA complete A4 upper w/ RRA lower containing mostly Colt parts, BM A2 carry handle).
I'm getting it sighted in, using 50yd to start. I started way low. The rear was nearly bottomed out, and on the "6/3" mark (not 8/3 since it's a carry handle). Is it better at this point to lower the front post to get it spot on? I figure I shouldn't need to lower the rear since 50yd is about the closest I'd be shooting, and would want plenty of available elevation for farther distances, is that correct?
Can anyone shed light on a good method for sighting in an AR's irons??
ps. I was using the large apature rear... It is my understanding that this is for closer distances?? Am I correct in doing so?
[edited to add post script.]
The zero is set with the front sight. The adjustments at the back are for distance, with the numbers respresenting roughly the distance in 100s of meters. There's a very good method over on the Maryland AR15 Shooters' Site called the Improved Battlesight Zero. With it, once you set your sights set up you can go from 25 to 600 meters by dialing the knob on the rear sight.