colorado bob,
I have seen a number of big-game animals (meaning larger than deer) killed with both Nosler Partitions and Swift A-Frames, including Cape buffalo. I dunno what "swear by Swift A-Frames" means, but in my experience Nosler Partitions of the same caliber/weight penetrate just as deeply, and sometimes deeper.
This is not denigrating the A-Frame. It's a fine bullet, but what many hunters don't realize only front core is bonded, and the jacket over the rear core is thinner than the Partition's--which also features a rear core much harder than the A-Frame's.
This is why A-Frames tend to expand wider than Partitions, particularly in the rear end, which often bulges due to the softer rear core shifting foreward. This is also why A-Frames typically don't penetrate any deeper than bigger Partitions of the same weight and caliber, and often not as deeply.
As I noted above, bigger Partitions with the jacket wall moved forward usually generally retain 85-95% of their original weight, which is exactly why they penetrate deeply. In fact, the 286 9.3mm Partitions will normally penetrate more than 250-grain Barnes TSX's, but not quite as deeply as 286 TSX's.
