TATELAW-
I've used both the Sierra's in question from my .243 Win. On close shots, the 85 gr HPBT Game King was a bomb, coming apart when it struck a rib on an average sized doe at close range, about 15 yds. Using them at longer distances would make me feel better about their performance on deer. I like this bullet and have several boxes of them on my shelf, but it's not very tough. Of course, with the experience you already have with them, you're probably well aware of their limitations.
I've also used the 100 gr. Sierra Game King from both factory ammo (Winchester Supreme from the early 90's) and as a handloaded bullet and it worked pretty well from my .243 Win. The only time I had anything resembling a failure with it was completely my fault. I was in an elevated blind and had an average sized buck come in on the heels of a hot doe. I was lined up on the crease behind his shoulder and squeezing the trigger when he started to whirl due to the doe moving. The 100 gr. SPBT Sierra hit him on top of his rump, shattering a big part of the pelvic bone and putting him down where a finishing shot closed his eyes for good.
That bullet practically disintegrated and aside from some tiny fragments, there was nothing left of the bullet. Penetration was shallow, basically creating a large, but shallow void on top of one hindquarter, next to the spine. The shock to his CNS likely put him down, but I would bet that given time, he would have tried to drag himself off.
Every other episode I can remember with the 100 gr. Game King was routine with shoulder or behind shoulder shots resulting in full penetration and I don't believe I ever shot a deer with this bullet more than 150 yards and most of them were probably only 50 yds.
