The front core of Partitions is also a relatively soft lead alloy, with 2.5% antimony. Most cup-and-core big game bullets have lead cores with 3-4% antimony.
The rear core of Partitions is a harder lead alloy, so the rear end will retain its shape, but the exact amount of antimony varies a little depending on the specific bullet.
Apparently quite a few hunters still don't understand the Partition. John Nosler deliberately designed it as an all-around bullet for deer-sized game on up. He WANTED the front core to expand relatively easily, and fragment, because in his hunting experience (and he had a lot) bullets that fragmented at least somewhat killed deer-sized game quicker. But he also wanted a tougher rear-end of the bullet to penetrate deeper on game bigger than deer.
In recent years, however, somehow higher weight retention has become the measure of "killing power," for at least some hunters. These often complain about how the front end of Partitions performs, or even consider a "disappeared" front core a failure, like they would an empty jacket from a cup-and-core bullet.
AccuBonds were designed to replicate the basic weight retention performance of Partitions, but with a plastic tip for those who always whined about Nosler not offering a "tipped Partition." They do exactly that, but because AccuBonds don't have a Partition many hunters don't perceive the front-end weight-loss as a "failure," as they do when recovering a Partition without a front core.
