Some owner's manuals recommend certain springs be changed at specific intervals.
Usually when the used recoil spring is 1" or more shorter than a new one.
If buying a used firearm, sometimes it is worth the cost to replace all springs for piece of mind.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)