Firing pin spring question.

[shaneshot]

Why do they normally come with recoil springs?

I understand their purpose and action and why you'd change them if you changed to a heavier, or usually lighter firing pin. Except for a new build or wear, why replace? I'm getting a heavier recoil spring as one of the steps to be able to shoot some heavier/faster rounds. Almost all of them also come with a FP spring as well. Is it simply because they assume it is to replace worn springs and they add it as well for safety?

[sqlbullet]

If you move to a significantly heavier recoil spring then a heavier firing pin spring may be in order.  The heavier recoil spring will accelerate the slide faster back into battery, and along with it the firing pin spring.  When to slide comes to an abrupt stop at full lockup, you want enough firing pin spring to ensure the firing pin is not stopped by the primer.

[shaneshot]

Sounds too much like common sense. Now I'm thinking I should've figured it out by myself. Thanks!