I change action/recoil springs in my pistols whenever the return to battery starts to feel a little sluggish when the gun is dirty and dry. That's averaged somewhere between 8500-10,000 rounds.
The only pistols that I use 16 pound springs in are the beater twins...because the ammo is dirty...my home cast 200-grain SWCs with soft lube and 6 grains of Unique. The ones in my carry rotation get 14-pound springs, and so far, I haven't had to change'em. I don't shoot my carry guns all that much.
The beaters have seen nearly 400,000 rounds collectively, about evenly split. I don't shoot "softball" ammunition. The 200-grain bullets and the cast 230s get the same 6 grains of Unique for 870 and 820 fps respectively.
The impact abutments in both pistols...slide and frame...are fine.
it aint a big secret that in some cases a weak/worn spring can lead to timing issues and malfunctions.
Nah. The spring doesn't have any effect on the timing at all. The pistol can be fired without a spring, and aside from having to send the slide back to battery by hand, nothing at all changes.
One caveat.
If you want to try firing one without a spring, you need to use a FLGR system. The short GI type guide rod will get cattywampus and tie up the slide.