Hi mate you say "on the recall" by that i assume you mean whistle?
If i were you i would forget the whistle until you've got the obedience spot on just with voice commands. I would start the dog quartering in front at no more than 15yds MAX and use a 15yd check lead to keep control.
Obedience is key, stop, stay, sit, come back. Shouldn't matter what's going on around the dog i.e rabbits bolting, pheasants flushing etc the dog should be completely concentrating on your commands, only after that would i introduce a whistle. Your dog is only 8 months, still very young. I know a keeper that wont