Rifleman Q & A: Safe Ammo Storage Temperature

by
posted on July 11, 2017
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
ammo_storage.jpg

Q: I live in rural upstate New York, and summer temperatures reach in excess of 90° F—with car and attic temperatures exceeding triple digits. Is there a known “maximum safe temperature” for the storage of ammunition? What would be the ideal conditions to store ammunition?

A: Nitrocellulose, the primary ingredient in smokeless powder, is hygroscopic, which means it absorbs water from the air that can affect both shelf life and burn rate. Coatings and stabilizers, such as methyl and ethyl centralite, are added to prevent this. Unfortunately, the effectiveness of these compounds is reduced as the temperature rises.

The standard advice is to store ammunition in a “cool, dry place.” Manufacturers try to store powders at 70° F +/- 5 degrees. For handloaders, the best advice is to store powder in a cool basement or an interior room that is of “comfortable” temperature.

—Charles E. Petty

Latest

Taurus GX2
Taurus GX2

Review: Taurus GX2

From cars to cellphones, as a product gets more sophisticated, it usually also gets more expensive. And, as modern handguns get more modular and optic-ready, their prices tend to go up.

Rifleman Q&A: A Garand Puzzlement

"We are a father-and-son NRA member tandem in search of an answer regarding the branding of an M1 Garand rifle. We own an M1 rifle that has markings indicating it was a “lend lease to England,” and it also has a .308 barrel/sleeve."

$160K Raised For HAVA At SIG Sauer Event

SIG Sauer hosted its 9th Annual Honored American Veterans Afield (HAVA) Charity Golf event early last month and raised more than $160,000 to support disabled veterans.

Scout The Trail To A General Purpose Rifle

The search for a universal longarm—one suitable for both hunting and defensive scenarios—is a trek that involves a bit of doubling back.

Trijicon Releases Green-Dot RMR

For the first time, the Trijicon RMR will now be available with a green aiming dot, providing some benefits to shooters with astigmatism and red-green color blindness.

The Armed Citizen® Sept. 15, 2025

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Interests



Get the best of American Rifleman delivered to your inbox.