If you draw 28, If you have room you can cut 1/2" off making the arrow stiffer then add the weight up front to bring it back to tune. I would have sombody watch you draw to make sure you have the 1/2 to cut, i would hate for you to cut them and then find out in the heat of the moment that you draw 28 1/2"
With that said i would go with what Charlie said, if they are fling great with 100's go kill somthing and when you buy your next set and want somthing heaver up front try some 2117's or if you want somthing realy heavy try some 2020's