The reason you don't recover TSXs is that they barely expand (and at many velocities DON'T expand). What really matters for penetration is expanded SD, so they penetrate just fine.
What they don't do so good at is width of wound channel. I've seen more well-shot game lost with TSXs than any other premium bullet.
The advantage of a high unexpanded SD is that you can have your cake and eat it too if the jacket thickness and weight retention are suitable - a wide wound channel AND a deep wound channel. That's the strength of bonded/soft core high SD bullets like the heavier Weldcores. Their wound tracks are ideal. You can't get that with a low SD bullet - you can have one or the other but not both.
Have you recovered said TTSX that expanded and didn't expand?
