I have a DPMS AR with a 1-9 barrel and all I shoot in it is 50 & 55gr bullets. With groups between 1"-1 1/2" at 200 meeters.
Of the powders you listed I would go with the 4895. Varget, TAC, BLC-2, 748, might be a better choice. I use mostly BLC-2 with 50 & 55gr bullets, with TAC being 2nd. They are both ball powders and meter nicely. 4895 and Varget being stick powders do bridge every now and then going through that small neck. For high volumn shooting you might want to try TAC, it burns cleaner.