I keep them in the case. And as said before. There is a wealth of info on that brass and on the envelope. Like the date it was fired. That has to be some what close to it's birth date. Did the striker or firing pin hit center of primer. Is there a firing pin dent with a swipe on it indicating a bad recoil spring right from the factory or a sticking firing pin or striker. Is the rim of the brass buggered up from the ejector or extractor. Or does the pistol in question like to dent brass in any way. I never walk out of a store with a new pistol with out inspecting the brass. It's a good purchase tool. And yes,,,, I have refused to except the pistol. And if the seller wont let me look at it,, I leave.
That fired round is the one that is logged for some law dog's in some states. Heck who knows, maybe all of those bullets are photographed for the finger print on the fired bullet. But in my mind throwing that empty out or reloading it is akin to throwing away the manuals and such that came with your pistol.
Heck here in Oklahoma when you get your drivers lic and you wear glass's they ask you to take them off for your photo. Found out it's so law dog's can run facial ID software on your pic. Yeah know everybody is a bank robber and we can all commit serious crimes in front of security cameras. We must be tracked down yeah know.