Yeah, I expect you would need to go with the lighter weight XTPs. The 158 grainers in .357mm diameter are kind of hard, I think, much better suited to .357M than .38 special. I don't have any experience with the 125 grainers in that diameter, but I wouldn't be surprised if you told me they also don't expand at 38 snubby velocities. Core hardness is something commercial defensive rounds have gotten better at. Hydrashocks are out, HSTs in. Hornady has their Critical Defense loads, which run softer cores than the Critical Duty. I've always wondered how the Zero 125gr and 158gr JHPs perform expansion wise. They're not bonded or anything, so I would expect them to separate from their jackets as often as not, but I think that's a soft lead core.