"What handy Double rifle would you prefer?? Where would you try to shoot the Lion at short, short range--center of mass or somewhere in the CNS??"

Let's be brutally honest.
What rifle? The one you have! You're not gonna get a choice in such a situation.

Where would you shoot? You'd damned well better shoot at the center of the biggest part you can see!

Brain? Yeah right, where is it? Remember lion have "flat" heads and that head is going to be bobbing like Linda Lovelace in high gear during a charge.

Head-on maybe the end of his (her?) nose. A bit high and you're on target (brain), a bit low and you're likely to drive on into the chest.

Bear in mind, you did say "short, short range" that's going to give you ONE shot if you're lucky. Then again, for my personal taste, anything under 50 yards would be short range for me where lion are concerned - I just don't like the buggers!