My mare shakes her head pretty bad around the second barrel, she used to do it around all three barrels but ive found that she likes both my hands on the reins. i havent grabbed my horn around the barrel anymore and that seems to help with the other barrels, but shes still doing it only around the second. shes had her teeth done and has had the chiropractor adjust her and do PEMF, ive tried plenty of different bits on her including a hackamore, any tips?

I've never heard of anything like that. Is she young? Have you tried a tie down? Do you have a more experienced friend who could try her or critique your runs?