Does anybody replace their coil spring after a certain number of rounds fired as part of a maintenance schedule ? If so, is it
a good idea replace any other springs as well ?

At least for M&Ps used for self defense, people in past threads have said to replace the recoil spring at anywhere between 3,000 to 5,000 rounds. Also, if you're noticing brass flying differently than usual, it's probably time to change it.

I'm not going to change my recoil spring until I get at least 3K rounds through it. I believe that S&W says 5K, but they're so cheap there's no reason to wait too long.

When I do update the recoil spring, I'll probably replace the striker assembly. Cheap insurance.

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