So on one hand, I'm super happy that my 7 month old pup will retrieve any bird that he sees fall.  On the other hand I'm not happy about the fact that about 50% of the birds have teeth gashes in the breasts.  I don't reprimand at all at this point, but what should I do?  Should I just start focusing on the hold command?  Any ideas?  

 That's what I thought, thanks PB.

Sorry to kind of hijack this thread, but can someone elaborate on how to teach a dog to have a 'soft' mouth, or point me the direction of good videos/guides?

I usually don't define it in terms of "Soft" mouth, but "Butter"-mouth (as in Butter-fingers). In other words, I want my dog to hold a bird with enough force to actually HOLD it, and not drop it. Dropped birds (when alive), are running birds, and so a dropped bird is a potential lost bird. This is especially true in heavy cover where you DEFINATELY want the dog to be holding the bird with enough force to keep it from escaping. Where I hunted last year, there was really heavy grasses, thickets of thorns, and willow - where the dog could go, but I had real issues. Force-training Sadie was necessary because I really did not want to think about where I was shooting when the bird was flying over these heavily-covered areas. By the end of training, I felt confident that if I brought the bird down, and sent the dog (and the dog could find it) she would bring it back to me. Conservation of game was key - I did not want to leave wounded, or dead game in the field.

As far as "Hard"-mouth issues, it is pretty easy to define the extremes.  I have read stories about dogs eating (entirely) live game, or pinning, and ripping the bird like a toy.  If the bird is not suitable for eating after the dog is "done" with it (a.k.a. - you can pry the bird from the dog's mouth), then, it has a hard mouth.  Some minor gashes in the breast may, or may not be significant - provided the bird is still suitable for the table.

nails...  I don't know.  I have heard of this approach.  I just have visions of my dog going after a bird/toy with nails in it, and aggressively grabbing it, squealing, spitting it out, and never picking it (or another one - in the case of a bird) up again (ok, I am being dramatic...). 

I think a trained hold is a way to go. Hard Grabs are addressed immediately.

I agree with tgatto. I train my dogs for hold and have never had a hard mouth issue. You never want to do anything that may give the dog a negative association with a bird. BTW my oldest dog catches doves in the backyard and when she brings them to me they are still alive. She has an incredibly soft mouth.

I don't think anyone was adversely commenting on Force Fetch.  That is the right way.  I also understand that using nails has been used in the past - so have other very painful methods of training.  I believe that with a solid Force-Fetch program, and patience, you can get there without using it.  My comment was that I prefer not to go that direction (using nails) - regardless of how many decades it was used for.  I also believe there are many ways to come at training issues.

Many World Renowned trainers today don't associate the use of training with nails, or barbed wire, or anything like that with development of a "soft-mouth".  Graham, Lardy, Hickox, and others stress solid training in FF (particularly the "Hold") instead of re-training of a softer mouth after a habit of hard-mouth has been established.  These trainers will generally recommend a chuck under the chin if the dogs starts chomping away at a dummy during Hold training, and the use of different objects (hard dowels, brissle brushes, paint rollers) to encourage a soft-mouth.

Again, (IMO), I want to avoid causing injury to the dog in any way, and nails in toys and frozen birds seem to have the natural consequence of causing punctures in the dog's mouth.  I just want to avoid that, and would look for another way.  I have found it better to use brushes, and other items during "Hold" Training that essentially effect the same behavior while reducing the risk of physical damage to the dog.

I don't believe that is being "half-arsed", and it leads to the right behavior in the dog without risk of injury to the dog: