The goal isn't to have a "high percentage" of animals recovered. It's to recover all of them. Without a good exit wound, there's no way you can be sure of that. An exit wound also speeds the animal "dropping" since it facilitates blood loss.
I have yet to hear a single reason why one would want to use the failure prone Bergers instead of the many reliable bullets that are readily available.
Used a 270 gr Swift A-Frame from my .375 H&H on this blue wildebeest and the bullet did not exit. The shot was around 100-125 yds away.
Guess we were lucky to even recover it,since there was no exit wound for it to bleed out from.
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Take your responsibilities seriously, never yourself-Ken Howell