Regular Wear
Glock considers regular wear on the handgun to include any stress imposed upon it by normal use. Glock considers normal use adherence to the general guidelines as described in the owner's manual, including the proper loading/unloading of the weapon and the use of recommended ammunition. Glock also recommends that you keep your weapon clean and lubricated. There are two parts on the Glock handgun that are subject to wearing out and are covered by Glock for replacement; the guide spring should be changed after approximately 3,000 to 5,000 rounds and the magazine springs after about 2,000 rounds.
Aftermarket Parts
Glock guarantees its parts, but not the parts of other manufacturers designed for Glock pistols. Any damage caused by parts added to your pistol, whether as a replacement for an existing part or added as a modification, such as the installation of an external safety, voids the warranty. Glock will still provide any repairs that you need, but you will be charged for services.
Unauthorized Work
Glock provides clear instructions on how to disassemble the weapon and to what extent you are authorized to do so. Glock does not guarantee any unauthorized work by either you or any third party, including gunsmiths who are not recognized by Glock, resulting in damage to your weapon.
Faulty Ammunition
Glock clearly specifies that the weapon is to be used with factory-produced ammunition for your particular model. Any damage created by using homemade reloaded ammunition or by using an improper caliber, for example shooting .357 SIG ammunition through a .40 caliber barrel, is not covered under warranty.