On my pistols, I usually replace recoil springs every ~5k rounds and, assuming I can find a full spring kit, all the springs every 10k. I only have a few pistols that I have put over 10k rounds through. When ammo was cheaper and I had more time and fewer kids, I would shoot about 5-6k a year. I only had 4 firearms back then. Any time I buy a used pistol, unless it really looks like it has never been shot, I replace all the springs as I have no way of knowing how many rounds have actually been through it. SIG used to make it easy by selling a kit that had all the springs and roll pins included. I still have a few of those around as I usually ordered several at a time. If I can't find OEM, I buy Wolff service packs if possible. Probably excessive, but something I have done since taking classes at the SIG Academy in the 90s. At the time at least, the instructor recommended the 5k recoil spring replacement as cheap insurance against battering some other part of the firearm to failure. It made enough sense to me that I have just always done that.