Newer to bowhunting. Addicted. moving from a 2007 bear truth to a new bear motive 6. I would like help with what arrow weight would be best to maximize speed but also produce good KE. Im shooting a carbon express and nap spitfire combo at 450gr currently. Broadheads are 125. im going to shoot 70lb and 30 inch so speed should come easy as the IBO is 350. Id like to shoot 320ish all set up. Help!