Hal
Yes, plenty of buffalo have been taken in OZ with the 9.3 cal.
John
Maybe you might be able to get the plains load to regulate and set the scope up to make the rifle an all round proposition.
One non-plus, for my way of thinking, is that it is harder to achieve a really solid mounting for the scope on some doubles as opposed to most bolt guns. There often seems to be a lot of unsupported scope length protruding behind the rear scope ring on many doubles.
There are ways of getting around the problem of course.
I think you should buy one straight away and start experimenting.