Has anyone worked with this combination yet?
Results?
No, but it should work well.
I have used enough 7977 now to get a feel for the approximate burn rate, which can change slightly in different applications. Decided to try it in the .257 Weatherby (where Hodgdon also doesn't have data out yet), using H1000 data reduced a couple of grains. 7977 got the same velocities with about a grain less than H1000, or at least my lot of 7977 did with my lot of H1000.