The iron sights on an AR-15/M16 look like this:
(Picture shamelessly stolen from http://www.ar-15.us/223_vs_762x39.php)
I’ve never used them before and was skeptical about their effectiveness (seriously, how much does the Army/Marine Corps know about iron sights anyway…)
Well! Here’s me at 25yards marching my sights to zero:
Here I am at bench rest with sand bags at a clean target:
…and here I am sitting with no support other than my arms:
…THEY WORK! Holy Toledo!
BTW: The ammo was the PMC 55 GR stuff in my BCM 14.5.