Help my dog is a nob head

[mushroom 13,268]

Right since the last post I've been out everyday training the retrieve is spot on, hand signals getting there (still more practice with left and right but she does understand). Whistle commands one tuneful pip sit and look at me very good even when running out to a retrieve, two short pips change direction yep coming along. Worked out where the real issues lie, she cannot be allowed to go after running game she will not stop, listen or return until she has fulfilled her obsession which is a bit of a cock coz wouldn't mind her helping out mates lurchers in the future. But as a lad off here knows shes a deaf nob when it comes to a bunny running infront of her, the funny thing is if she catches the bunny she'll bring it straight to my hand unharmed (not that she has caught an uninjured healthy bunny mind you) but she has chased/hunted down pricked rabbits before now everyone retrieved alive with no broken bones or injuries besides a pellet hole

 

So the question is how do I increase her steadiness to bolting game??? or break through the blinkered mentality she gets into when on the chase???

or should I face facts and only use her for retrieves