I have some prime hunting loads that have been in storage for about 20 years. These loads were very accurate in my .270 Winchester Kleinguenther K-15: 160 grain Nosler Partitions at about 2910 fps for big game and 140 grain Sierra Boattails at about 3140 fps for medium game. I don't recall the powder or amount.
They have been in a commercial storage unit without climate control.
Does anyone know if accuracy - or, worse, safety - would degrade from such storage?

Well, former farmer, your profile does not say where you live, but, if you live where it gets hot, I would suggest you dump them, or, just pull the bullets, empty the powder and reload them.
Peter.

I`d shoot it.
Lots of 50 yr old+ mil-surp still being used. I`ve shot stuff I loaded in the 70s for a handgun that sat in my basement almost 20 years and worked just fine.
Unless the ammo is showing corrosion I don`t think you`ll have any problems. That`s provided you are shooting it in the rifle it was worked up in originally.

My dad just gave me a couple of boxes of handloads he has had in his garage. They were loaded in 1986 and 1987 the all shot extremely well.

I loaded up a bunch of ammo for one of my rifles that doesn't get shot often, so even though they are 18+ years old I still have about 100 rounds left, which will last a few more years at the current rate of use. They are hunting rounds, but I fired 5 of them a couple years ago at a target and everything still grouped 1.5 inches at 110 yards, which is plenty accurate for what they are needed for.

A couple of years ago I came across a loaded 45 magazine that I had forgotten about that was at least 10 years old. It fed and fired just fine which for me also answered the question about whether or not it is harmful to keep a magazine loaded for an extended period of time.

Shoot some and see. Deteriorated powder will not increase pressure. I have some c. 1917 caliber .303 brit ammo loaded with Cordite that still shoots to spec. It has been stored the last 15 years in my garage south of Houston, Texas (as in HOT!) without issue.

What I do find sometimes is reloaded brass gets brittle in 10-20 years and suffers neck splits. Never had that problem with surplus; just reloads.

The only time I ever had any sort of problem with stored ammo was with .380 pistol cartridges .

I had loaded up dozens of boxes of rounds , they weren't max loads either .

I shot some over a few months the rest were stored inside my safe dry clean and in plastic ammo boxes .
I got busy with work ,as time went on I got several new guns . I forgot about those cartridges in other words .

Well 17 years later I was cleaning out my safe ( It's a small room really , not a typical gun safe ) and ran across those loaded rounds .

Oh boy I'll break out the Walther and punch some paper . They worked just fine ,nice an accurate 25 Yd. paper punchers !.

As I picked up my brass I noticed the cases had split , almost each and everyone of them !. What the hell happened ?? .

I pulled a dozen from different ammo boxes and weighted each charge . I knew what they were loaded with as I always label my ammo .

I could find NO REASON what so ever for split cases , yet they had nearly all split ! .

It's a mystery to me ?. I've never experienced that in any other reloads I've done . Now over 40 years of reloading I've reloaded a box or near a zillion !.

Herco 4.1 gr. 88 grain hollow point somebody's projectile cci primer . Just in case any of you were wondering !.

Shoot Straight Know Your Target . ...

As Dr. K experienced and others have referenced, brass can be come more brittle over time. I have never found this to be a safety problem, only a problem in that the brass is lost after the one firing.

My father brought back a box of .45 ACP from WWII. I take out a round every few years and fire it, just to see how it's doing. Never a failure in this old steel-cased ammunition. Let me assure you, it has been "stored" in some of the most adverse conditions possible in terms of temperature variations.

Simply set up a chronograph and see how your stored ammo is doing. My guess is that it will perform in a way that is indistiguishable from when it was first loaded.

If you followed good storage procedures, go ahead and shoot it. I've found no problems with my own handloads often dating from the 1970s. I store most of my ammo in either a safe or .50 cal GI cans with a bag of silica gel or two. Have killed deer with some of this "old" ammo, and I can remember shooting competition with some fifty year old 7mm Mauser ammo.

LLS

Shoot 'em!
I have systematically shot 3 rounds each year from a batch I handloaded in 1962 using the Lee "pound 'em in the sizing die with a hammer" method.
180 gr Speer in a 30-06 with IMR 4064 powder.
NO DIFFERENCE in group size- I still have the old Win Model 70 I got in high school and have used the same gun to shoot these reloads to remove any further variables. The still chrono the same as they did 5 years ago-that's when I bought my first chronograph.
If you kept them in a dry environment you should have perfectly good ammunition.

Gary

I just shot about 30 rounds 4 weeks ago that I loaded in 1990. Since then, they've been stored in Ohio, Iowa, Arizona, and Alabama.

No problem.

Shot some 1917 .303Br rounds a few years back at a 500yd NRA range here in New Zealand. It was a Commemorative shoot so we dragged out some old rifles. Through my No.4, it shot a 46.3/50 so they weren't bad! Nearly all the necks split so clearly brittle.

If they aren't obviously corroded, have a go.

Chris NZ

I found some loaded ammo gave me problems after a fair amount of storage. I hadn't gotten all the lube out of the case neck before seating and the bullet really kind of "bonded" to the brass. What I would do if I was you is check them by putting them in a seating die. Try seating them about .010"deeper. If they move easily you're good to go and don't need to do the whole batch. If they sort of "crack loose" then I'd seat the whole batch slightly deeper....this breaks the storage bond.

I had my first and only case explosion with 20 year old+ ammo. Seems time/moisure had stuck the bullets just enough to give me the scare of my life! I still have the split case to remind me how things can go bad.

I pulled the remainder of the bullets and found them to all be stuck very good.

My advise...pull the bullets/ resize/ and reload/ with the same bullets but new powder/primers.

I took some 16 yo ammo for a 7mag and shot it. It worked great. No special storage; it hadn't been sealed nor anything. Just laying on a shelf in the component cabinet.
I didn't Chrony it but it shot to the POI it was supposed to. That surprised me most of all as the rifle (gotta love those Rems) hadn't been shot in 10 years.
As posted, powder doesn't get stronger as it gets older. If you've a Chrony, I'd check out the velocity and let that decide.