those are about the worst pellets out there. Win, lose or draw shooting the pellets he recommended will tighten up your groups. A tune makes a huge difference as well, most people get thier springers tuned, even when brand new.
I would sight in @ 10 yards to start and then move out to 25 yards, after that individual ability will account for 75% of your accuracy. I do well at 25 but start to drop off at 50 yards although I'm not what one would call a disciplined shooter.