Join Date: Oct 2011
Location: Illinois www.saddleonline.com
I'm chiming in, this isn't really a bitting problem and another bit is unlikely to fix it. Your mare is getting excited and ignoring you - and your bit.
You need to work on getting her to focus, when she starts getting too strong, ask her to circle, turn or otherwise focus on your commands. You need to capture her attention and make her pay attention to your cues.
"Riding: the art of keeping the horse between you and the ground."