Yaddio,
The original Barnes X's tended to shed their petals on impact, but when they didn't, and were recovered, many hunters liked to brag on the 100% weight retention. Randy Brooks thought losing the petals would damage more tissue, but after hearing the 100% bragging for a while decided to change the heat-treatment so X's would tend to retain their petals more often--due to the old business suggestion that the customer is always right.
Randy told me this himself during a mule deer hunt, not long after the TSX was introduced.