I've got 9 recovered TSX bullets, none have an "X" on the bottom.
If there's enough energy to expand the projectile such that it sticks in the hide, it's going to penetrate beyond what the pic shows. If it's not expanded and just poked that hole, it'd fall right out the 1st time that muscle flexed it'd squirt out.
In '14 I shot an OLD rutting Mule Deer. 1st shot @ ~50yds got him through both lungs and he continued to chase his herd of does as if unfazed. 2nd shot he's going almost dead-away and I run a shot along the ribs, the bullet tumbles, and I found the projectile sticking out on the point of the front shoulder very much like the pic in the OP. I very much regret not getting a photo. I was excited to see a projectile I could recover and didn't think before I nabbed it. There was extensive "bruising" all along the ribs and front quarter as the bullet tumbled around along it's path so it was easy to follow the bullet's entry and almost/partial exit. I'm a "270 guy" and my hunting parter for that trip is a "30-06 guy". It's been 7yrs and we still laugh about how the .270 barely penetrates.
