There it is 8208xbr. I have heard great things. Sorry but I don't have an ar15 so I don't know the what the coal limit is. I am feeding from aics mags so I can get quite a bit of length. What I do know is I used to load 73 into an argument magazine with great success as well as 77smk the 75 a max may or may not fit. I would think it should though. FYI those 75 hpbt are holding moa and less to 775 if I reed the wind correctly. 75 a max can do it better just like the 80s and especially the 90s. But for you coal is your biggest worry. If you don't mind the extra cash the 77smk should work well but I would research the 75amax first.