I don't think .5" is that big of a deal. The arrow charts are not even that accurate. You could try a heavier tip and see what happens. The best ways to change your spine are to change the length of your arrows, play with the poundage, or change the tip weight. Your arrows are already to short according to you, you can't raise the poundage any, so the only thing you have left is adding weight to the tip.

By the way, what kind of tear? Left, right, up, down? Are these the same brand of arrows as before, are they both beman hawks, just one is a half an inch shorter? Or are they two different brands of arrows. If that is the case things may be different. Any time you change something on your bow, the tune can change. If it were me I would just retune the bow for the new arrows and go from there. It can't be that big of difference, can it?

Paul