Good quality springs will usually last for many years, but it never hurts to exercise the gun at least once a year when you (hopefully) change out your ammo, checking the springs at the same time, obviously. I have seen Remington 870 factory mag springs that worked just fine after two decades, most of that time spent under full compression, but the Wolff replacements are so inexpensive it would not hurt to think of changing out the mag spring every few years. One BIG issue is to be sure and keep the gun...including the mag tube and spring...clean and properly (lightly) lubed. If a spring gets a rust pit in it, I can guarantee it will eventually break at the pit (weak point). With personal defense firearms, cleanliness really can make the difference between living and dying.