What must one do to their AR to make it a good iron sight rifle? Things that come to mind is 1/4MOA rear sight but what about the front post? I see/hear about different post sizes. How do you know whats the right size for you? Am I missing anything else? I'm probably going to be using a 16" barrel and attempting out to atleast 300yrds but maybe even 600. Man silhouette targets.

I like bushmasters' thin front sight - you can be more precise with it.  Another thing is to use a smaller aperture rear sight(bushie too) and this makes it slightly easier to center the front post, especially for 100 yds and beyond.  However, not sure I do anything but use a thin front sight on your 16 inch as the short sight radius probably wouldn't permit you to use the full capability of even the 16 inch barrel.  Some folks, and I'm sure we'll hear from them, do very well with a 16 inch barrel.  I'd rather have every advantage for long shots so I stick with a 20 inch barrel and long radius.

If your looking for an accurate 16", check out the Dissipator.  20'n sight rad and very comfy to handle.  Its my next rifle!         [coffee]

Well IMO if ya want the 300-600  shots it would be best to get a 20" barrel for most people. Longer sight radius , helps the aim on longer shots for most people and you will be getting the required lenght to get the bullets to maximum speed and propellent burn. Alos you can buy the NM rear sights but Im telling you the A2 sights and even the A1 are plenty accurate for 300-600 hitting siloetts targets. If your wanting to compete with paper targets , then NM rears will do you alittle good.But you would have to put alot of rounds through your A2 sights before graduateing in skill level. 20" is the way to go for what you described. IMO WarDawg

Armalite and bushmaster both make a 1/4 MOA DCM square front sight post which is slight thinner and has sharper corners for a distinct sight picture. The Armalite post is slightly narrower at the front end, and is rectangular. Combine this with 1/4 MOA A2 rear sight assembly, hooded .040 or .034 aperture and you will be about as fine as you can go with iron sights. Note that this is good for X-ring shooting, but not good for combat or CQB as it takes longer to aquire your sight picture.

Alright, thanks for the help and tips!