My ten yr old got his first bowkill this past fall with a left bevel Zwickey No Mercy.
He was shooting a forty pound compound, with a four hundred twenty grain arrow. He centered the lungs, breaking a rib on the way in, and passing between the ribs on the way out. (pass thru)
The deer only went forty yards and was down...blood all over.
The cutting edge did NOT hold up, and was curled in severely. Not the tip, the edge. I would say the damage to the head occured upon entry, when it broke a rib.(between ribs on the way out)
Next year, he will be shooting a broadhead that contains steel that is harder. I feel the edge should have held up much better than it did.
Beat to death or not, the question was specific.
I feel the edge did NOT hold up as expected.
In addition, the commonly referred to "s" shape exit was NOT present. The entry hole was much wider than the cutting diameter of the head.
We did use left wing fletching, with a high FOC carbon arrow.
I honestly feel the No Mercy heads we had, were much softer than the several dozen Deltas that I have, and have used for years.
JMHO.