Again, my test on 165/168gr bullets out of my Wby and water filled gallon milk jugs.
Muzz vel 3150 with all bullets. Nosler 165gr BT, 168gr J4, Hornady Amax. At 75yds, the BT vaporized two jugs and broke apart the third, bullet went on to punch a nice 1 1/4" hole through a piece of 2" lumber.
The Hornady and J4 blew up two jugs but only peppered or slightly poked holes in the third.
My experience with the Interlock/SST puts them tougher then the BT. So this gives you a relative comparison of penetration at very high impact vels.
Personally, I love the SST as they are such an improvement aerodynamically over the Interlocks. I have hunted with the Interlocks for many seasons in my 303 and '06. At moderate impact vel, penetration on deer vertebrae, shoulders, etc, is excellent. I would not hesitate to use the SST/Interlocks on any game within shooting range of my '06 or Gibbs.
Jerry