AR-30: best retumbo loads so far 85.0 and 91.5, best H1000 loads have been 82.5, and the most accurate and consistent powder has been RL-25 at 83.5 and 89.1.
Really depends on the OAL. I have found that in my DTA i can put a ton more powder but they are almost 3.9". I use 95 grains of retumbo behind a 300 grain.
