RE: 30 caliber bullet for Elk?
With the 300, 150gr 165gr 180gr bullets loaded to maximum pressures do not have significant differences in trajectory out to 500 yards.
The difference at 500 is only a couple inches, less than that at closer ranges, assuming same bullet type.
The recoil is only two pounds more on the 180 at max than it is on the 150 at max. Assuming same powder bullet rifle.
Really no reason to use anything but the 180 if you are elk hunting.
Try the Barnes triple shock this bullet is not as finicky as previous Barnes bullets.
The Nosler Partition is a solid performer.