Nice little .357
You should be able to swap in a lighter mainspring and possibly a lighter rebound slide spring. If you do swap any springs and use the gun for personal defense be sure to run at least 100 rounds of your chosen load through it to make sure you have consistent ignition and function before relying on it. Before you do that though I'd dry fire it a few hundred times, they usually smooth up noticeably with some cycling of the action and that might be enough to call it good. And if you do or will use it for defense I would prefer to run the factory springs - just my 2 cents