They may be adequate for the animals that you may be hunting and then again the guide service that you are going to use may not allow them. The best thing to do is to contact the guide service that you plan on using and ask them about it.
I know that here in North America there are guides for moose and bear in Alaska that require a minimum of a .30 caliber and up.
They would be adequate for the smaller of the plains game, but if you're planning on getting into the kudu and eland size animals, you will want to move up to at least a good 30 caliber or better rifle with a good bonded bullet. As critter mentioned, when you pick out a PH to go with, it would be a good idea to get their recommendation to make sure when you get there that they don't say your rifle is too light for the task and make you use an unfamiliar one of theirs,
In the spring of 2007 I was the unfortunate recipient of an injury cause by a damaged carbon arrow that shattered on release of the arrow. I was in the yard going to take a few practice shots before dinner and the second arrow is the one that did the damage. That day will forever be burned in my mind. After I release what happened I made mistake #2 I pulled the tail shaft of the arrow out of my hand causing more damage.
Thank goodness that my wife was home and was able to...