I've loaded 150 game kings for years and hunted deer with 'em from a 7mm Rem Mag out west of the Pecos in Texas and in the Guadelupe Mts of New Mexico just north of the Texas state line. I can tell you with that combination, don't shoot anything inside 100 yards. You'll destroy all kinds of meat. It works out beyond 100 yards.
I've used the rifle for 4 deer and went to a .308 at much lower velocity using a 150 game king which works well on deer. Ditto, my .257 Roberts with a 100 grain game king. I'd gone back to my tried and true .257 Bob, but I'd won this .308 as a door prize at a gun show and I'd learned to very much like it on pigs and deer. These loads are very accurate, too. A guy at the range who had some spare ammo for 7 mag gave me a box since he'd gotten rid of his 7 mag. The loads were very accurate, Federal Premium 160 Nosler Partitions. These were quite accurate, but were plain base with a lowish (I thought) BC. Actual BC is .475 and when I ran the exterior ballistics, it looked surprisingly good and I worked up a load with 'em and loaded 50 rounds for the trip. Well, I had an opportunity recently to take an elk hunt. I wanted to take the 7 mag since that's what I bought it for even though I knew the 308 would work despite the Game King bullet. The .308 had completely penetrated many hogs for me straight through the shoulder with that load. But, I wanted the 7 just because. I took a very large cow elk at 200 yards with it. The Nosler Partition penetrated completely on a shoulder shot. I know that game king would have not totally penetrated. It would likely have disintegrated on that clavicle. That bone was huge and thick.
So, if you wanna be SURE on big game like elk, go controlled expansion. Otherwise, on deer, six of one, half dozen of the other except perhaps on something sub caliber like .223.
That's my experience, FWIW.
