Dry fire and spring life

How often do y'all change recoil, hammer, and firing pin springs? How much does dry fire play into spring life? Ty for the time!

Coil springs i have never changed.  This includes my old High Standard 107  & Colt Gold Cup 45 acp, both from the 1970s. I did test the recoil spring of the High Standard. It was ok.

Flat spring/strain screw  was changed in my S&W M28 when i installed a new hammer nose (firing pin). 
I have seen flat springs in Winchester lever actions  become weak from age. Flat spring are likely to break at times. 

If  dry firing, use snap caps. To many other parts receive wear thats not wanted. Imo.   I never dry fire. Train with a 22 lr. 

If its not broke , dont fix it.  I am age 75 & lazy , shooting about 2 times a week.