Has anyone tried to determine the max seating depth for their Ar 15, and if so what was your oal. According to my hornady book you can go to 2.39" for their 75 grain bullet. It will not work through the mag but can be shot one at a time. So, this being said. When the usual round for a 223 is set at 2.25" oal. And a round at 2.39" is safe to shoot before you hit the rifling. What does that say about people try all different types of rounds and spending untold amounts of cash. When they are a min. 0.14 off rifling. I think we can all save a lot of time and money if we know exactly what the max seating depth is for each individual rifle.