I've shot more than 100 animals with 175 SMK's from a 308 in the last ten years and they remain my first choice, though I have been using Barnes a lot in the last couple of years because they tear up less meat.
I am limiting my comments specifically to the 308 / 175 SMK combo, not others. I could care less what Uncle Fester did with a different combo.
The 175 SMK was designed specifically for terminal performance out of a 308, not a thing to do with target shooting.
Like all bullet and rifle combos, there is an optimum shot placement.
The 175 SMK tends to tumble through and provide deep penetration with significant wound channels from the tumbling usually exiting if the animal is inside of 200 yards.
If you like lung shots, go with a soft rapidly expanding bullet such as an Amax, Ballistic Tip, or Partition.
Lung shots generally do not result in DRT results. The animal is going to run 50 - 100 yards before running out of oxygenated blood. In an open area that is no big deal. In the brush country, that is a nightmare.
SMK's, Barnes, E-tips and other bullets are better for high shoulder, or quartering through between the shoulders, where there is more bone and muscle to provide resistance and thus energy transference.
Optimal shot placement with 308 175 SMK - and most other combos for that matter.
Exit wound of a 308/175 SMK with a high shoulder shot.
Note the large hole through the spine - easy tracking job.
I've posted this many times, but made it to show the 308/175 SMK in action.
308 with the Amax