I have used SST's in a couple of Handi-Rifles:
95 grainers in a .243 to kill a doe antelope at about 200 yards; broke the off-side shouler and exited. I was kind of impressed...not much meat damage really;
then a 117 grainer in a 25 Remington to kill a doe mule deer at about 70 yards. No major bones were struck,the bullet exited. Again, I was satisfied with its performance.
Velocities were moderate, neither load would be considered maximum. However, elk are big, tough animals. One would have to really be careful of the shot agle, trying to place a bullet in the vitals without hitting any large bones with SST's, I think.