CZ 75 vs. P-01 recoil spring

[black43]

I have a 75B omega that has 2k-2.5k rounds through it and the recoil spring has a lot less resistance than my P-01 that has about 300-400 rounds through it. I'm wondering if these guns come with different strength springs and this is normal. No issues with feeding, cycling, etc. I'm just wondering when the recoil spring needs to be replaced, typically, or if the P-01 just comes with a stronger recoil spring.

To make sure I'm saying the right part, it's the tension on the slide as it's racked and the gun cycles.

[M1A4ME]

Shorter/lighter slide and one less locking lug on top of the barrel for the Compacts vs. the full sized pistols may require a stronger recoil spring to compensate for the design changes.

[jurek]

I'm just wondering when the recoil spring needs to be replaced,

When you start having failures...
If you have factory FLAT spring, it should last for 40K rounds... which in some cases means "forever"