I have about a half dozen Thunderheads left over from when I used to shoot aluminum arrows. Now I shoot 5575 Goldtip carbons. Now I know NAP makes little metal washers called a ubar for use with carbon arrows but, I have shot these heads on these Goldtips at my targets with no loss of any blades. Have any of you shot deer with Thunderheads and carbon arrows without using the ubars? What were your results? Any blade retention problems? Thanks for any help.