African Perspective
I am a PH in Africa and have hunted throughout the Continent both myself and with clients from all over the World. From my experiences the Calibre choice is generally a more important decision than the Brand. As a general rule of thumb, the smaller the calibre, the more accurately one tends to shoot. I own and have shot rifles ranging from .222 right through to .500NE. My .223 and .243 generally give me tighter groups than any of the larger calibres. I have made numerous one shot kills on 2000LB Eland Bulls using 55Gr bullets in my .223. I firmly believe in 'placement over power'.
There are many great Brands on the market today. Historically, the Americans are the pioneers of the bolt-action rifle and(in my opinion) have always produced the very best of them. The Winchester Model 70 happens to be my favourite, hands down, but you cannot go wrong with Ruger, Remington and Savage. CZ is a very popular brand in South Africa.