The standard 16# recoil spring was designed for standard 230 gr hardball loads. It will work fine with medium loads, you might want to consider say a 12-14# spring for light loads or a 16.5# variable, or the next lower weight variable.

If your pistol ejects rounds that land right at your feet the spring is probably a little to heavy. If ejected round land 10-12 feet away the spring is too light. Ideal is ejected round land about 4 to 6-7 feet away.

The really light weight springs are for either very light loads or for compensated pistols. With a compensator you can get by with lighter springs. The heavier weight springs are for really heavy loads or guns with lighter weight slides.

You need to consider changing out your recoil spring when it gets 2-3 coils shorter than a new unused spring.