Bobby,
SST's have been toughened up considerably since their introduction--much like SOME Ballistic Tips.
A good example is one of my local friends, who handloads 162-grain SST's for his family's several 7mm rifles, mostly 7mm Remington Magnums. He killed a bull elk last fall with his 7mm RM at around 150 yards, the SST entering behind the left shoulder and breaking the right shoulder. He found it perfectly expanded under the hide on the far side, with the core firmly inside the considerable shank left on the mushroom.
Last fall I took part in a gun-writer hunt in South Texas, where close to 30 pigs and deer were taken with .308 Winchesters and factory loads with 150 SST's. The largest pigs and deer weighed close to 200 pounds, and not a single SST was recovered, even on severe bone and angling shots.
Most of today's hunting bullet manufacturers tweak their products to improve performance, both in accuracy and on game.
It is surprising that bullet companies do not advertise what they have done to improve performance. We are therefore left with beliefs that are no longer true. While grateful for Mule Deer to update us, it seems to be a marketing benefit largely ignored.
