My gelding has started to try and throw or drop the bit out of his mouth. I'm using a medium length shank, curb bit that I got when I bought the saddle and all of the tack. My horse was trained and well broke to ride when I got him but I have no idea what kind of mouthpiece the previous owner(s) used as the situation I got him from is a little unique.
He has never really liked the curb bit and always seemed to "fight" against it, no matter how "soft" I am with it. He neck reins very well, he just seems to be fighting the bit.
I am thinking of changing to a true snaffle and seeing how he works with it. I don't really think he needs the curb bit, his action seems to be that he is fighting only the bit, not what I am trying to get him to do.