Maybe the rounds are too short and hanging up on the magazine lip, feed ramp or inside the magazine. The feed ramp might need polishing. Have you tried different magazines? Presumably you've ruled out a slide-related spring problem. Maybe you got a dud box of ammo or the powder charge is too weak to cycle the slide reliably.
If you're asking for factory-loaded LRN or FMJ RN .357 Mag ammo, the only one I'm aware of is Armscor 158gr FMJ.
https://us.armscor.com/ammo/357-magnum/