Leaving magazines loaded has zero effect upon the springs. It is the constant flexing cause by loading and shooting that wears springs out.

I have something over 50 magazines in my vault and the only time they are empty is when I have just emptied them shooting and haven't had time to reload them. Some of them have been loaded for three of four years between shooting.

And yes, the correct term is magazine. A clip is something that is used to charge a magazine. An M1 Garand uses a clip, so does a BroomHandle Mauser. Just about everything else uses a magazine. The two terms are not synonymous.