I will say that, in my opinion (after many personal range observations and much internet lurking), that Glocks will be most reliable with stock factory recoil springs, UNLESS you need to tailor a gun to a particular (say very light target-type) load. I have lost count of the times that someone has reported functioning problems with a Glock, and then these problems go away after the user is convinced to change back to the stock recoil spring. I am also of the opinion that a person needs to show a fairly high level of skill and be very attuned to their pistol's particular recoil characteristics before any changes in springs will really show any benefits. Not saying you you couldn't possibly benefit (as I don't know you or your skill level), but most folks can't really tell the difference, and even some who can, can't exploit that difference and change it into a useful savings of time between shots.
Also, you need to be prepared to spend a LOT of time experimenting with your gun/ammo combo to find the correct spring setup. This can be very expensive, either in time or money (or both).
I personally only use stock springs in all my Glocks, and spend the money saved on practice ammo and gas for range trips.
Somewhat of a newbie to the site but I could not help it when I read the thread, even if it is an old, old thread.. I have a G34. Set up for competition. Different trigger spring, firing pin spring, firing pin safety spring and a different recoil/action spring. Polished. Deburred. I shoot 147 gr Berrys plated bullets with a 13# action/recoil spring. Too slick and too dangerous to carry but it ain't failed to go bang for a lot of rounds.
If you, like all the rest, are shooting factory loads 115gr or 124grs, the only thing I would suggest to try would be a 13# recoil spring.
When a semi is fired, muzzle flip is attributed to over coming the strong recoil spring. With a light spring resistance is really met when the spring is almost compressed. In reality, the recoil spring's main function is to return the slide to battery. The other springs I have changed affect the trigger pull.
Try it and report.
It's not, at all, uncommon for an experienced Glock pistolero to use an assortment of different recoil springs. I keep 3 different weights for each of the Glocks I own. -1# down, standard issue, and +1# up. This accomplishes several things for me:
1. I'm able to increase or decrease the amount of perceived (controllable) recoil I experience. A fast pistolero, who's concerned about his split times, will tend to go lower on recoil spring weight - Often significantly lower than standard.
Why? Because his slide will travel faster, his muzzle will flip less, and his front sight will be more quickly recovered.
2. Most pistol shooters will opt for a heavier recoil spring in order to experience a different, but similar, result. The split time between shots will be longer; and the muzzle rise will be greater; however, the actual recoil impulse, itself, will seem more manageable.
There's, also, the matter of what brand of ammunition you are using? If you're getting your ammo from Wal-Mart a -1# spring might be the most appropriate to use. If you're using Israeli or European ammo, then, using a heavier recoil spring is going to be a lot easier on the gun.
Recently, it's amused me to notice that one of the common, 'quick fixes' for the feeding problems with Glock's new 4th generation pistols is to recommend going significantly lighter on the recoil spring.
I've seen recommendations from knowledgeable Glock gunmen as low as -5#'s. (Yeah! I guess that would cycle anybody's pistol, huh.)