Stand in front of a full mounted lion starting to leap. Stand 6 feet away from it and look into or up to its eyes and you realise why the .308 will feel puny.

I think it is better to be over-gunned with something that bites back rather than under-gunned.

Many writers have said (I have no lion hunting experience) that a .375 H&H is an ideal lion calibre.

Added to this the PH I hunted with in Zim said he had had several lion charges in the tall grass of Tanzania and believed a .500 A-square was the ideal lion charge medicine as it generally will drop them no matter what (ie less than perfect shot placement) when "they come boiling out of the grass". (I like that term - "boiling out of the grass")