There are three main considerations to, uhm, consider when selecting arrows- Spine, Weight and Straightness. Aluminum gives you all three at the lowest cost. Some carbon will be the same cost, but will be all over the board in the three specs. Higher priced Carbon or Carbon/aluminum will be much better in all three specs, with some (ACCs) rivaling aluminum in consistency.

Have you weighed each of your individual finished arrows? Have you spin tested them?

Perhaps the reason for you volleyball sized groups at 25 yards you referred to in another post is due to your arrows, not you Chances are, you don' t have many matched arrows in the ones you bought. If you are going to shoot a heavier arrow anyway, you' ll get better specs with aluminums for less money...