I'm going to be sighting in the iron sights on my RRA AR-15 this weekend. This in preperation of an Eotech XPS2-0 to come soon, I hope. I just want to have my BUIS zero'd in just in case of an unlikely Eotech failure during a defensive situation. I read a lot of articles suggesting the 25 yard sight in, and then I ran accross this article. Sounds like this sighting in process might be a great idea. The only problem, I don't know what grain .223 or 556 he was using. I run 223 Rem Federal 55gr FMJ through my rifle. And plan on using this round 99% of the time as it's the cheapest I can find, and have about 1000 rounds in magazines ready to rock.
Give this a read, and let me know what you think. THANKS