Whilst hunting dangerous game, you want to tilt the odds in your favor as much as possible. DG safaris are both expensive and, by definition, dangerous. The least expensive component of your safari is the ammunition. Buy the best, most proven ammunition there is. Don't endanger your life or the lives of those in your party by using unproven ammunition just to save a few bucks.
BTW, how did the PPU 7x57 ammunition group in your rifle? Did you chrono the ammunition? If so, would be interested in your results.
