We had a Sierra person join in a thread at TFL on this, a few years back. CAmopng other things, the discussion compared the 150-, 165- and 180-grain bullets, with hollow point, spire point, flat-based and boat-tailed shapes; all Game Kings.
For the 150-grain: Don't drive the boat-tails above 2,900 MV or thereabouts. The jackets are thinner. (Which is why I had a bullet blow up in a mule deer's neck at 30 yards.) Flat-based, no problem.
I've found that the 165-grain HPBT will blow a really big exit hole in smaller white-tails. Right at fist-sized. I'm dubious they'd really be good for penetration on an elk.
At 500 yards on steel, the 180-grain SPBT makes notably more crater than either the 150-grain or the 165-grain. I'd think it would be a good elk bullet.
I've been able to stay within one MOA with the GameKings at 100 and at 500 yards...
FWIW, my father killed a helluva lot of deer with the 150-grain Hornady spire point with basically the old GI powder charge. That's an MV around 2,700 or thereabouts.
I never had any problems on Bambi with the Remington 150-grain Bronze Point. Dunno, really, why I changed to the Sierras; probably because of the boat-tails and the longer probable shooting distances in my hunting area.
Art