I have heard people say they don't throw bumpers while teaching ff. What is the reason for this? Any opinions? I've been teaching hold for 3 weeks and he's ready for ff. Also, I have been shooting some crows for my pup and he seems apprehensive about picking them up. If I bring them home and tease him he will retrieve them sometimes. crows are the only thing I can legally use right now. Will ff help with this?