The 6mm she already owns is capable of about 100 fps greater MV than the 243, and uses the same diameter bullet. Therefore, technically speaking, for her to buy a 243 would be a (very small) step backward.
True, this is... but I was responding to "what is the lightest recoiling cartridge/rifle combination that would be suitable for elk hunting." I would use the 6mm and not buy a 243 but a 243 is pretty much the lightest recoil cartridge suitable for elk.
I guess I should have specified that I wouldn't buy another rifle. The implication wasn't as clear in writing as it was in my head.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.