I've got 4 of the older Sigs, with the internal extractor, and as Malicious Compliance stated should one of them break, I'd have an expensive "brick". Yes they're springy, and as long as you don't abuse them, they should last for quite some time. If you ask as to what kind of abuse... the primary one that comes to mind is having the extractor "jump" over the rim of a cartridge "in" the chamber already. The design, is that the cartridge's rim slides up from under the hook of the extractor when fed from the magazine, and the hook holding the cartridge rim against the breechface, until the fired cartridge case is withdrawn from the chamber as the slide moves to the rear, and being kicked out of the extractors grasp by the ejector after clearing the barrels chamber. These newer extractor designs allow a little more flexibility than the older internal types, but they can still suffer from the same scenario.