I have had a similar experience with AA2015 in my .223. It was accurate, but about 150fps slow with the same charges listed. Thing is, it showed pressure signs when I tried to increase the charge to bring the speed up, so I just went back to H4895.
I am not sure about DHN's AA1680, but in the case of your AA2015 the problem is that it was manufactured in 3 different countries. Israel, Czech Republic and now in Canada. The Canadian powder is a different burn rate than the previous powders but was never changed in any load book or burn rate chart
