Information from the Sporting Arms and Ammunition Manufacturers Institute (SAAMI):
Small arms ammunition contains explosive ingredients: A percussion- sensitive primer mixture and a smokeless propellant. It should be treated with respect and care in all handling, transportation and storage.
Ammunition should be stored in the factory carton or package. The labeling and identification on the original container help to assure that future use will be in the gun for which the ammunition is intended.
Ammunition stored in the home, retail outlet or distributor’s warehouse over extended periods in factory packaging, subject to the ordinary variations of temperature and humidity ranging from tropic to Arctic conditions, can be expected to perform satisfactorily and safely in the firearms for which it was intended if such firearms are in proper working order and condition. Extreme high temperatures (over 150° F) however, should be avoided.
Ammunition should not be immersed in water or exposed to any organic solvent, paint thinner, petroleum product, ammonia, etc. Such materials may penetrate a loaded round and reach the powder or primer; a deteriorating effect will result which may cause misfires or squib shots. The latter can result in a projectile’s lodging in a gun barrel, the obstruction possibly causing serious damage or injury when another shot is fired.
Ideally, home storage of small arms ammunition is in a locked closet or cabinet out of the reach of children and uninformed or incompetent persons. Both guns and ammunition should be stored out of sight and reach of children and others not physically or mentally capable of giving them correct, proper use and respect.
Storing guns and ammunition in locked auto trunks may be convenient, or required by state or local law, during short periods when moving to and from the hunting field or target range. The possibilities of extremely high temperatures make it sensible to remove firearms and ammunition from vehicles following the trip. The passenger compartment of a closed car when exposed to the sun often develops an extreme high temperature and is thus not a desirable spot to leave ammunition.
For long-term storage, any method/system should:
- Keep ammunition dry
- Protect ammunition from theft, unauthorized usage and fire
- Maintain low relative humidity levels
- Have stable temperatures between 50-70 degrees Fahrenheit