I can understand why you would not think so. While it does not carry the energy over distance that the SST carries, it certainly has done well for my needs.
Here is a hunt at the same property. I killed 6 hogs with TNT, most were 200 lbs and on up. I found 3. The landowner found 3 the next day with the help of buzzards. None were far from where shot or dropped in place. I had to shoot 1 hog twice because the bullet went behind the ear, missing the spine and skull, and just blasted a large hole through the neck. The landowner reported that the 3 he found were in the "200 lb range."
https://youtu.be/xNkEupGBrKY
Here, I shot two smaller boars with TNT at Distance...
https://youtu.be/tQkAfKBbn2A
Another long shot...
https://youtu.be/huhWOJezxGE
Here are more TNT vids...
https://youtu.be/rYhTfMfdKeo - a little fun with this vid
https://youtu.be/X-PBcjCopfU
https://youtu.be/KcQI9nzt4wY
I have also been using it while on other hunts with Ben and Dave...
https://youtu.be/hz3DeQwsQKw (Dave using TNT handloads)
https://youtu.be/lZPr_ZYTgbE
So I have been using the Speer TNT for a while in my Grendel. As with other ammo and hogs, if the bullet does not do significant CNS damage, the hog will run. This happens with 123 gr. SST, Berger 130 gr. VLD-Hunting 129 gr. ABLR, Berger 130 gr. OTM, Cavity back 105 and 118gr., etc. However, when hit in the boiler room, even when the TNT round does not overpenetrate, the hogs seem to die fairly quickly after running a short distance, as would be expected from a shot in the same are with other hunting ammo.