RIPP, you are a shooter and you will know for sure.

Whichever for plains game, maybe a really light rifle.

But for lion...

How about this; since you know the .416 will kill everything totally adequately, all that matters is what you want to bring, and of course your shooting, and that is round-count and time-on-target.

But you WANT to take the .470, and the .338 is an option, and really, it is a great lion caliber, too. Ahhh, but that .470 keeps beckoning and you want to bring it, which is natural. Who wouldn't?

So, why not make a sort of game out of it, a contest of sorts. You have a couple months or more before the hunt, yes?

Pick some real, practical, field accuracy goals for lion. Real life speed and distance shooting {whatever the max range might be for lion in the area in which you plan to hunt}. Take your three rifles; .416, .470 and the .338. Be honest and strict in your shooting goals.

Pit the three against each other. If I remember correctly, you can get to the range a few times a week and plan to from here on in. So do so, and then after, say, three weeks, make an honest judgement. Which one wins? Which one do you honestly shoot the best with?

Whichever that one is, buy the bulk of your ammo and spend the next month and a half shooting it and your light rifle alone {...and your .22 of course