Perhaps they used these. They are very high powered sniper rounds.
You might be right, but even soft point sniper rounds in that caliber would not take the top off the way it didi.
Also, it doesn't fit the profile.
Chinese executions are so routine that they skimp on everything. They wouldn't use such an expensive round when the cheap ones will do the job.
Roaddog has a very good point though. I forgot, they do use the 14mm machine gun round, which would absolutely cause the damage we see. But again, the profile is wrong. Unles they were looking to make an example.
Which might explain a lot. Use a big bore, create big damage, take photos, let photos get smuggled out with the implication: "this is what happens to those who misbehave."
Best way to terrorize a political group.
The "Dragunov" SVD Soviet Sniper Rifle; 7.62X54MM/R.
See: http://www.kimdutoit.com/ee/index.php/ggps/dragunov_svd_762x54mmr/
The Dragunov is regarded to be one of the finest, most reliable tactical Sniper Rifles yet designed.