I am super impressed with everything Ive seen about the 300 PRC in terms of accuracy, ballistics, etc...
My only concern would be whether or not its really needed? Its got substantially more recoil than a 300 WM or 300 H&H (about 15% higher in most cases where Ive compared notes).. which either means youre going to have to increase the weight of the rifle a good bit to tame it, or work yourself through being able to mitigate the recoil (some charts I have read show it having as much as 42ft lbs of recoil energy.. which is more than a 375 h&h shooting 300gr projectiles by a decent margin.. although most Ive seen put it somewhere in the 38lb range)... and the increased range and accuracy, while very cool for long distance shooters, snipers, etc.. Im not sure really brings a lot of advantage when youre talking 0-400 yard shots (most places in southern Africa the shots are going to be A LOT shorter than 400 yards.. most are going to be in the 0-150 yard range, with maybe an occasional shot in the 150-250 range.. and anything beyond that is going to be pretty rare unless you are specifically asking the PH for long distance opportunities)...
I figure my 300 H&H is light enough to carry all day long in the field, easily gets me 1 MOA with about anything I feed it.. and has enough ooomph behind it to put down anything from an impala to a eland at up to 400 yards.. all while only producing about 60% of the recoil of the 300 PRC (on the highest tables Ive seen... realistically its probably about 25% less).. and ammo is readily available both in the US and in most places in Southern Africa... so thats the direction I went...
All of that said.. if you already own a 300 PRC, like it, shoot it well, etc.. by all means take it to Africa and enjoy it! its not common for ammo not to arrive (although it does happen).. if that occurs, its almost guaranteed your PH will have a camp gun for you to use until the ammo makes it to you.. and you'll still have a great hunt.. (in Africa you just roll with the punches.. sometimes things happen...)...