Somewhere in your house there is a case of 9mm you paid too much for in the spring of 2020.
You remember the price. Everybody remembers the price. You stood in a line, or you refreshed a website at eleven at night like a man buying concert tickets, and you paid north of fifty cents a round for range ammo that had been a quarter a round in January. And then you got it home and you put it somewhere and you have never once shot it, because it was never for shooting. It was for not running out.
That ammo is six years old now. And every few months somebody at the counter asks me the same question about it with the same slightly guilty face, so let’s deal with it.
It’s fine. Almost certainly, it’s completely fine.
Modern ammunition does not have a shelf life the way milk does. Smokeless powder is chemically stable, the primers are sealed, and the whole thing is sitting inside a brass envelope engineered to keep the weather out. People shoot military surplus from the 1940s and it goes bang. I’ve seen crates of stuff older than the guys arguing about it on the internet run clean through a rifle all afternoon.
Time is not what kills ammunition. Heat and water are what kill ammunition.
Which means the only real question is not how old it is. It’s where you put it.
If it’s been in a closet inside the house, in the original boxes, at whatever temperature you keep your living room — stop worrying, go shoot it. If it’s been in an unconditioned garage in Phoenix, or a shed that swings sixty degrees between January and July, or anywhere the humidity does what it wants, that’s a different conversation. Not a panic. A conversation.
Here’s what to actually look at, and it takes ninety seconds.
Pull a handful from the middle of the box, not the top. Look at the brass. Clean and bright is clean and bright. A dull patina is nothing. What you’re hunting for is green — verdigris, that crusty blue-green bloom, especially down at the case mouth where the bullet seats and around the primer. That’s corrosion, and corrosion down there means moisture got in and did work. Look for any case that’s swollen, cracked at the neck, or has a primer sitting proud of the pocket.
Then do the thing nobody does: pick one up and feel the weight against another one. Bullets don’t fall out of cases on their own, but a round that’s been rattling in a hot humid shed for six years can lose its crimp. If one feels loose, turn the bullet with your fingers. It shouldn’t move.
Found green on a few? Pull those and quit worrying about the rest. Found green on a lot of them? Don’t throw the case away yet, but don’t make that your defensive ammo either, and definitely don’t make it the ammo you hand a new shooter.
Which brings me to the actual point, and it’s not about chemistry.
The problem with the 2020 case isn’t that it’s degraded. The problem is that it’s unknown. You have never fired a single round of it through the gun you’d use it in. You don’t know how it feeds in your carry gun, you don’t know where it hits, you don’t know if that particular lot is the one your pistol hates.
Ammunition you’ve never shot is not a plan. It’s a hope with a receipt.
So here’s the whole job, and you can do it this month. Take a box out of the case. Shoot it. All of it. Run it in the gun you actually own for the purpose, in the magazines you actually use, and watch what happens. If it runs clean, congratulations, you own a verified case of ammunition and you paid 2020 prices for peace of mind you can now actually bank on.
And if it doesn’t run clean, you just found that out on a range in November instead of somewhere worse.
Rotate it, too. Shoot from the old case, buy new to replace it. The pile stays the same size, the contents keep moving, and you’re never again the guy with six-year-old ammo he’s afraid to find out about.
