Agree with DLee.
If you would like some suggestions of people who aren't just some cowboy who can snub and ride a bronc, but really understand what Buck is doing, send me a pm and I'll get you a list.
What you have, is a troubled horse.
but without fail during each and every ride the breaks get jammed on and the bucks comes out.
Your horse is now confirmed in the idea that when things get upsetting, s/he should buck the rider off.
Incidentally, that is how Ray Hunt came to meet Tom Dorrance. Hunt was an exceptional horse trainer, and he had one horse he just couldn't figure out how to not buck like the dickens every ride. This horse that Ray couldn't train, was Ray's introduction to an incredible understanding of difficult horses.
If you can find a 'cowboy' with the timing to teach her that she has no choice...you might get past the buck but she will never fully trust her rider. It's the part where she learns she has no choice, that is the problem.
I think you've got a tough nut, and you need someone who really understands how to get her past her troubles, teaching her discipline without teaching her she has no choice.
And it is possible that the horse has an intractable pain issue. In which case, you won't make a safe mount out of her.
I wouldn't send the horse back to the first trainers. Obviously they missed something or rushed it. My mare was on the lunge for monthS. Sent to training in April, wasn't backed until mid August. She was a pill. My trainer doesn't rush anything and waited to progress until everything was perfect on the lunge. The rider stayed on the lunge for 2 monthS. When ever she got riled up they'd stop and start again the next day. The goal was to NOT let her learn she could buck with a rider. She's now with a young rider getting miles and she's been perfect with her.
I agree with the above poster... now that she has this 'trick' of dumping people, it's going to take the right trainer.
Yea.. I'd like to think there is a time line on where a horse should be at x months after being started but like people they're all individuals. The horse has to dictate the time to a certain extent. Mine wasn't rushed (my bank account was the only one upset about this), but now I have a really well started horse that's going faster in her training because the initial start was done very well.
I won't make any suggestions on how to fix your problem horse, as I haven't worked with him. However, I feel a need to respond to the complete ignorance of the training referred to as "Cowboy Training". Most trainers, have had to go to extremes because of the problems that were created in the first place due to a lack of "General Horsemanship". Then people freak out when the solutions are applied. None of which need to be employed with their own horses. I have had the pleasure of working with many of these gems that have become dangerous. Just about every person with a problem horse, owned a horse with a human problem. I will not speak for every trainer out there, as I have witnessed some of the self proclaimed "Experts". Instead of talking about what is CLEARLY misunderstood, and labeling it "Cowboy Training" keep the dialog to what you known for sure. Since many of the comments are from those that don't train colts and fix problem horses, it obviously isn't their area of expertise.