TSIBINDI,
Thanks for the specific example of a 300-grain Partition "failing"--which doesn't contain any evidence except a buffalo that disappeared with the evidence of what happened with the bullet.
Kevin Robertson's suggestion contains a lot of speculation, and a misunderstanding of how expanding bullets work. With rare exceptions, mostly long-range "hollow-point" bullets like Bergers, expanding bullets start to expand the instant they hit skin, and are completely expanded by the time they penetrate their own length. This has been proven many times in test media, including videos of bullets shot into clear ballistic gelatin, as well as big game.
Also, the phrase "set up" is often used by British hunters, and others who descended from Brits. It means "expanded" or mushroomed. I don't know why Kevin used both "set up" and "expanded" here, but unless soft-points somehow fail to expand somehow, that's how they work. (I know Kevin Robertson a little, and published a couple of his articles when I was editor of a hunting magazine, which is why I'm wondering about the redundant phrasing.) If a Nosler Partition doesn't penetrate deeply because it started to expand on a buffalo's chest skin, then the same could happen to any other softpoint, including several that expand even more widely than Partitions.
But we don't know what actually happened on that particular buffalo, and neither does Kevin.
Plus, as I mentioned in an earlier post on this thread, an even more experienced African PH, Kevin Thomas, killed hundreds of buffalo with 180-grain Partitions from a .30-06 when culling on a big ranch in what was then Rhodesia. I'd read Kevin Robertson's book when I hunted with Kevin Thomas the first time, and as a result specifically asked him he had any trouble with 180 Partitions penetrating buffalo with frontal shots, and he said no, not even on mature bulls.
