The only thing I can think of is get down in grains to produce a 3000 fps load with Grand and see what happens. Maybe somewhere in there it cleans up groups.
Had the best fishing yet in 20+ years in Panguitch, Utah. I only used 2 flies. A mayfly dry pattern and a San Juan style worm. All on a 3 weight rod. Caught dozens of each in tiger trout, cutthroat, brook, rainbow and brown. So much fun!
9.5 in a 26" 280AI
10.5 in a 26" 7RM
I wear the seat out of my pants glassing, rather than the soles of my boots in a SW desert. I think I manage these in a medium weight well enough for shooting in open country.