I voted for the .338.

Hunted plains game with a .30-06 the first time and while it does OK wasn't satisfied with it especially if less than perfected shots were taken or when the projectiles weren't doing what they should.

Second time just took a 375 and didn't regret that but was worried about the possibility of a long shot one day.

I think a 338 spans the gap and has the bullet weight for the larger plains game such as eland but also can be loaded to enable some longer range potential even if it isn't ideal for this activity.

But my 375 will probably continue to do the job.