Casting that country mile

[Nomad60]

After using spinning reels my whole life, I finally bought myself a bait caster reel (Shimano Calais CL200A) and put it on a medium-heavy 6' 6" St. Croix rod. I have the variable brake system set at 50% and have experimented with the casting knob after setting the reel up as recommended at this site. I primarily use a 1/2 oz. spinner bait and 1/2 oz. chatterbait on 10 pound line and my problem is; I can't seem to cast out more than 20, 25 yards. If I loosen the cast control knob any looser, I start getting backlashes while the lure is flying through the air. I've tried casting overhand, sideways etc, but just can't get any distance. I've watched other fishermen with bait casters and they get longer distance, using smaller lures. Is it just a matter of practice, practice, practice, or am I missing something?