LCP,
I changed my recoil spring at 200 rounds, rather than the recommended 250 rounds. The original one had lost almost two full coils in free length compared to a fresh one.
The ammo I've been using is 115 grain & 124 grain Speer GDHP, plus some white box Winchester 124 grain practice stuff. There were 20 rounds of 147 gr. GDHP mixed in, but the gunsmith at my local gun shop convinced not to buy more. He said lots of good guns choke on the 147 gr. rounds, so why push my luck.
My next range session (with the new spring) - no problems at all.
Note: I'm one of the lucky guys who have been basically trouble-free so far.