I know I talk out my rear all the time on here and don't know jack according to some on here. But the 400's are right on the money if his arrow is the same length as his draw length. If it's shorter it's stiff. So, why do people keep telling him to go to an arrow that would be way overspined for his draw length.
He only has a 27.5" draw length. If it were longer he wouldmight needa stiffer arrow. The wrapshelp stiffen the spine. Again, I don't know jack.
Even with my draw length the 340's would be on the stiff side with 100 grain heads.