I would not worry about the weight of your current arrows. I am a little confused with what kind of broadhead you are using. Is it a Grim Reaper or a NAP Spitfire? Either way, they are both mechanicals and you should not be using them with your light weight setup. You are not making enough kinetic energy for a mechanical head. Switch to a fixed blade and you should have enough speed and KE to have pass throughs.