i love gp-100s.The .357 Magnum is the most outstanding versatile caliber made, in my view. And it's too bad Ruger stopped making its amazing Security-Six line of revolvers!
125gr JHP: Against humans, there is no greater manstopper than the 357 125gr JHP. It's even been used to drop mid-size deer, if you're a hunter. Gun writer and former cop Mas Ayoob has said the 125gr JHP is the gold standard for use against humans, even if they're wasted on drugs and otherwise difficult to stop.
COP KILLER BULLETS: In the late 70s/early 80s, cities all over the United States were trying to ban Teflon-coated bullets that the media insisted could kill cops. Of course it the Teflon had nothing to do with it. It was the steel core that caused it to defeat all the bullet-resistant vests in use at the time! Thus, fueled by the media, all Teflon-coated bullets were targeted for banning.
What the media didn't know, but Mas Ayoob (and the NRA, for whom I worked at the time) did, was that the 125gr/JHP also could poke holes in the bullet-resistant vests cops wore all day long! Had that been known at the time, the entire shooting world would be far different today! It was a dark time then. Even today, a 125gr/JHP is extremely uncomfortable to be shot with, even with a vest. True, it won't penetrate modern vests, but it it's worse than being shot with other handgun loads.
ADDENDUM: The media never was successful in teaching violent criminals to attain the Cop Killer Bullets. But the issue did cause criminals all over the United States to increase tactics such as laying in wait and ambush attacks. Anyone with reloading equipment can produce steel bullets. But that was too much trouble for violent criminals, so they would hide in stair wells and wait for cops to show up. Then they would go for head shots when the cops showed up. So the media actually taught violent criminals to kill cops!
158gr/JHP: Finally, the 158gr JHP .357 is a great round to use for hunting. Like the 125 JHP, it's a violent round. But it's very good for penetration. It's not to be used for two-legged varmints if it can be avoided, but it's great for most other applications. Years ago, in California, the California HWP had a running gun battle with a violent criminal. They had 357 158gr/JHPs, the bad guy had a .45ACP. He was able to take out three HWPs before one of the California cops got him.
I love the 357 Magnum. The ABSOLUTE BEST ones made today are the S&W 686 in 4-/6-inch models. Next in line are the Ruger GP-100s. I could go on, but everyone has their own views.