They're both excellent. However, they are "apples & oranges", in that they are not built the same, nor are they intended for the same uses!! The Partition Jacket has a soft front end for maximum explosive damage at close range, and good expansion farther out after velocities are low, plus its' indestructible rear half continues to penetrate NO MATTER HOW FAST IT IS GOING, OR WHAT IT HITS!!

On the other hand, the BS is the same as the Nosler Ballistic Tip - it has a heavy solid base that supports good expansion and gives acceptable penetration on thin-skinned stuff, but the front end is soft and not bonded. Therefor, BS bullets tend to be more frangible and give a lot less penetration than the Partition type. The BS is intended mainly for lighter game, like deer and antelope vs the Partition Jacket, which works for ANYTHING, BUT gives somewhat slower kills on light stuff than the BS......

The new Nosler Accubond performs more like the Partition bullet, but, design-wise, it is essentially a Ballistic Tip with a bonded core.