I ordered a bunch of replacement springs for my Smith 6906 and Sigma. At $3 a peice it's cheaper than replacing a mag. I also have 12 of the 15 round mags for my G19. I have no idea how old they are but have never had a problem. They are probably at least 10 years old. My questions is- Do Glock mag springs have a long life loading and unloading? My Smith mags were all getting weak and were shorter as well. The Glock springs still seem nice and powerful, still tough to load the last couple of rounds. Does anyone else replace their springs after a few years or are Glock mags known for lasting an extra long time.