Thread: ar15 223remmingon FNB brass 62gr adi fmj bm2 powder 205MAR primer

Originally Posted by USAGuns

I think FNB brass is actually 5.56 milspec brass, which means it has slightly less case capacity the 223 REM commercial brass. For 20 rounds, just use starting loads and blaze away.

My mistake, it is 556 head stamped, and I had to de-crimp so yes, milspec. Ive used ADI 2208 in them and the max load seemed close, I got to 0.2gr over and that was as hot as I'd go as accuracy went to pot with vertical stringing (3/8s Horiz v 1.5inch vert). I'll load 5 of each going up in 0.4gr and see how it goes.