Who's shooting the Knight Disc Extreme, and what are some longer range accuracy loads you like?

What powder, in your experience, has the best accuracy combined with the least clean-up/maintenance factors in your opinion? Particularly something for the shooter that doesn't shoot that often, but wants things to go smooth when they do.

Is it a 250 yard gun?

Pellet powder users?

Leupold 4.5 - 14 x 40 Long Range reticle?