Reading through this thread and seeing what everyone has to say makes me feel better about deciding on the Calibers going to South Africa with the wife and I in may Deb will be hunting with her 30-06 and I with my 308. I've been working up some reloads and this is what I came up with, both rifles will shoot 180gr TSX
30-06 using H4350 and IMR 4320 for the 308 and using my Chony as the reloading book is way off on the speed of the bullet the 308 will be 3 fps faster then the 30-06 and both rounds will drive tacks at 200 yards.
I agree with all the contributors on the merits of the .308. It is an extremely popular caliber in South Africa and if you do your bit it wont let you down. If I may comment on the Blue Wildebeest, it has a smaller frame than Kudu for instance. But pound for pound it is one of the toughest game animals in Africa. Study bullet placement on the Wildebeest, take it through the boiler room and it has to go down.