Steve,
I've shot a couple of animals with the GS 150gr (1 in 10 twist 308 win). Never managed to recover any bullets. Quality of the bullets are good, and they grouped really well in my 308Win (under 1/2 MOA) from standard Rem.
Only "mishap" I had was when I shot an impala(100 pound antelope) at about 12 yards on the shoulder (long story as to why shoulder and not head). The bullet glanced off a rib and ran the length of the body just under the skin. According to GS it was as a result of the bullet not yet stabilized. Shot numerous animals from 60 pounds up to 250 pounds with no problems. Full penetration shoulder to shoulder.
Moved to SMK's for better BC's and reliable data from Sierra Infinity program.