Short answer: quality AR-15 magazines can be stored loaded or empty. Springs mostly wear from being compressed and released over and over, not from sitting compressed, so the bigger risks are bent feed lips, dirt and moisture. Store magazines on edge in fitted slots, clean and dry, and label which are loaded.
Should you store magazines loaded?
This is one of the oldest arguments at the range. The common engineering view, shared by spring makers and many magazine manufacturers, is that a spring wears from cycling - repeated compression and release - rather than from staying compressed at a steady load. Good modern magazines kept loaded for long periods generally feed fine. If a magazine starts to misfeed, replace the spring or the magazine.
Some shooters still download a 30-round magazine by a round or two for easier seating on a closed bolt. That is a preference, not a storage requirement.
Protect the feed lips
Bent or cracked feed lips cause more problems than tired springs. Do not store magazines loose in a bin where they can be stepped on or crushed. Store them on edge in individual slots so nothing presses on the lips, and use dust covers if they live in a bag.
Keep them clean and dry
Dirt inside the body causes drag; moisture rusts steel magazines and springs. Wipe them down after a dusty range day, let them dry completely, and keep them somewhere with stable temperature and humidity - the same rules as long-term ammo storage.
How big is a magazine case?
| Holds | Hinged lid (mm) | Slide-off lid (mm) | Printed as |
|---|---|---|---|
| 4 x AR-15 30-rd magazines | 116 x 213 x 76 | 118 x 203 x 78 | one plate |
| 6 x AR-15 30-rd magazines | 169 x 213 x 76 | 171 x 203 x 78 | two parts |
| 4 x Glock 17 magazines | 116 x 155 x 42 | 118 x 145 x 44 | one plate |
| 6 x Glock 19 magazines | 128 x 179 x 42 | 130 x 169 x 44 | two parts |
Each slot is the magazine's thickness plus 1.2 mm clearance with 1.6 mm walls between slots. Magazines stand on edge, so the case is as tall as the magazine is deep front to back plus a little headroom. Build yours in the case builder - mix magazines, rounds and gear in one case.
Label loaded and empty
A simple habit: keep loaded magazines in one case and empty ones in another, and mark the lid. Our lid marking prints text such as "AR-15 / 6 MAGS" into the lid in a second color, so it cannot peel off.
Frequently asked questions
Does keeping a magazine loaded wear out the spring?
Generally no. Springs wear mostly from repeated compression and release, not from staying compressed. Replace a spring if the magazine starts to misfeed.
Should I download my 30-round magazine to 28?
It is optional. Some shooters do it so the magazine seats more easily on a closed bolt; it is not needed for storage.
How do I protect magazine feed lips?
Store magazines on edge in individual slots so nothing presses on the lips, and avoid loose bins where they can be crushed.
How big is a case for six AR-15 magazines?
About 169 x 213 x 76 mm (6.7 x 8.4 x 3.0 in) with a hinged lid.
Can magazines and ammo share a case?
Yes. Fitted slots for magazines and pockets for rounds can sit side by side in one custom case.