How often should you change your magazines/springs?

After a little research I learned it’s the cycling, not constant compression that wears down mag springs. Is there a good rule of thumb for how many rounds it takes until there’s an issue? My carry gun is an HK P30SK and I was planning on ordering spare mags for the range, to not have to load and unload defense rounds every time. I also have a CZ SP01 Phantom for HD with ~850 rounds through it and the mags are noticeably easier to load, so I’ll probably be ordering new springs for that. I use Aguila 115gr FMJ for plinking and 124gr HSTs for defense. via /r/CCW https://ift.tt/2I09M3J