That's just something you'll have to play with. Add weight until the arrows shoot down the line you want.

I know guys that have gone to brass inserts, brass weights and stainless steel points - built up nigh onto 400 grains total in the nose of their arrows, some of 'em! - to get spined out properly with carbons. Very tip heavy arrows but they fly suprizingly well.

Hopefully you won't have to go that extreme.[&:]