I have been over there and also looking up AR loads on Load Data. Just load the BT and Parition and see what I get for accuracy. Expecting the BT to be more accurate. Trying Benchmark right now, as that is what I have in stock.Also. There is a grendel forum with lots of info and load data. Some helpful guys there. I was using 8208 xbr with good results in 120 gr class bullets. Grendel load data is on the weak side due to the 52k max pressure for bolt thrust. You can expect 2400 ish with 120's and a 20" barrel.