OK. My nominees for the various "best factory loads" for various tasks in THIS gun (6" barrel GP100):
Best load for defense against *dangerous* animals (black bear, boar, Griz only in a DIRE situation when there's nothing else left): Cor-Bon 200grain hardcast @ 1,250fps or so. Reason: major penetration, big power.
Best deer hunting load: Georgia Arms "Deerstopper", 158grain JHP hunting load at close to 1,500fps. Based on the XTP projectile, it's a "deep punch" expanding hunting load.
Best personal defense load: this is the big controversy. My pick: the Proload 158grain Gold Dot personal defense load, rated 1,200fps from a 4", figure another 100fps in a 6" tube. Why? Because I'm concerned about some of the various hot defensive JHPs going "too fast" in a long tube, and breaking up too much. The Gold Dot projectile resists breaking up because the jacket is bonded to the lead "chemically", and the 158grain version is going slower than the 125grain Gold Dots so out of a 6" tube, it's less likely to fly apart at 6" velocities. The 155grain 10mm load at similar energy levels has produced some spectacular expansion effects so I would hope the somewhat similar 158grain 357 would do likewise.
The other advantage: the momentum of the 158s let you make the "pelvis cracker" shot, to drop somebody armed with a knife/club/etc in their tracks.
Why Proload? Others may be loading the 158grain Gold Dot as a personal defense solution, but their rep for quality control is excellent.