Well, a week later I got to the range today. I suspect that I was putting it off expecting to find something wrong with the rifle and not wanting to do the dance with Taurus again.
I had some 38 Special FMJ RN Herters I believe (brass case), some Remington green box 38 Special FMJ HP +P and bought 25 rounds of Fiocchi 357 Magnum at the range, both of the latter ones nickel plated cases.
No case bulges like I experienced with my reloads. Perhaps a tiny bit of expansion at the base but I haven't measured them yet, just a visual observation. Very relieved so far that serious issues haven't been found. The 357's were certainly not "weak sisters" as I loaded up the 605 with five of them and gave it up after three rounds. No fun there at all, though in the Rossi they didn't feel much different than the 38's.