Tejano,
Randy Brooks told me 14 years ago, during a mule deer hunt, that the original X-Bullets pretty much lost their petals consistently, which he saw as a plus, since the detached petals resulted in more damage around the wound channel.
But then he started getting glowing reports from many hunters who had recovered Xs that retained all their petals (and hence weight). The reports weren't so much about killing power but 100% weight retention. This became an often-cited characteristic of his new bullet, both in hunting camps and gun magazines, so Randy (being a good businessman) decided to give customers what they wanted. He played with the bullet-making process until most would retain all their petals, especially if they didn't hit heavy bone along the way--but that was not his original intention, or or even what he considered desirable.
One of the interesting things about all this is the newer Long Range X-Bullets (LRXs) are built to open easier at longer ranges, where velocity has fallen off, so do lose petals more than the TSXs or Tipped TSXs.
