The Recoil Spring Assembly (RSA) on GLOCKS is a very important part of the operational chain that determines if the pistol fires or not. GLOCK highly reccommends replacing the RSA every 3 to 5 thousand rounds. Will the pistol operate longer on a worn spring, sure it will. Well, it might and maybe it won't when you need it the most. Obviously a clean pistol is going to offer less resistance if it is put together correctly and require little tension on the springs. But as it gets dirty and things like slide guides, chambers and firing pin components get sluggist the recoil spring has it's work cut out trying to return that slide to the battery position. I would like to offer this bit of advice, "Test your pistol when it is dirty." So, when is that or, what is dirty? Let's just say everyday you return from the range, wether you clean it or not. How's that? The test is simple and because it is simple, many people get it wrong. Let's try doing it the right way: -Point the pistol in a safe direction -Remove the magazine. -Eject any chambered ammo. -Lock the slide to the rear. -Physically check the chamber and mag well to ensure all ammo is removed. -Release the slide, point the pistol in a safe direction and -Pull the trigger. The RSA should be reasonably strong enough to move the slide forward and chamber a round even if the pistol is dirty, dry or, the ammo is not perfect. So, lets proceed with the test: * With an unloaded pistol, ***Point the pistol upright to about a 45 degree angle and keep it in that position during the test. ***Pull the trigger... Now while holding the trigger back pull the slide to the rear AND release the slide very (riding it forward with your hand) slowly. If you released the trigger you didn't perform the test. You have to hold the trigger to the rear during the whle test. ***The recoil spring assembly should be strong enough to return the slide completely forward and into battery. The test is designed to be quick and simple. It can be completed in seconds, wouldn't you agree? If your RSA passes then your test verifies RSA is strong enough to chamber ammo in less than ideal circumstances. Like I stated earlier, the RSA should be changed often. Heck if you can't remember when it was last changed, do it now. Yea, even if yours passes the test. Squirrel it away for a back up and start calulating when to order a couple more. They are CHEAP insurance to ensure you have a pistol that will carry you through the battle. In most cases that I have seen the RSA fail, the slide stopped just short of battery. Right around the time the barrel hood starts to enter the slide ejection port.