Favorite powder - .243 Win/55 grain NBT's
I spent some time working with RL15 and H380 last year in an attempt to put together a fast load for coyotes. RL15 eventually gave me decent velocity, but only o.k. accuracy. H380 gave me great velocity, but again, only so-so accuracy. When I say so, so accuracy it hovers right around 1 inch/100 yards. I know the gun is capable of better accuracy (at least with other bullets) as I can get sub m.o.a. out of Hornady 100 grain BTSP's all day long with IMR 4831.
If I had to live with what I have I could, but I want to ring as much of the potential as I can out of the gun.
With the above said, what powder(s) would you try next and in what order.