Ammo Storage

Military Ammo Cans: The Standard for Long-Term Storage

Surplus and new-production military ammo cans (M2A1 .30 cal, M2A1 .50 cal, and larger PA108 sizes) are the gold standard for long-term ammunition storage. Their gasketed steel lids create an airtight, watertight seal that keeps moisture out while the heavy-gauge steel body resists impact and provides protection from casual fire exposure. New-production cans are available in steel and polymer—polymer cans are lighter but lack the same seal quality as steel originals. Surplus military cans are widely available and still provide excellent storage when the gasket is intact. For bulk storage of rifle ammunition, 5.56 and 7.62 ammo is commonly stored in its original bandoleers inside .50 cal cans. For handgun ammunition, a .30 cal can holds several hundred rounds in most common calibers.

Plastic Ammo Boxes: Organization for Range Use

Plastic ammo boxes (MTM, Plano, and similar) organize individual cartridges by caliber in stackable, labeled containers. They are not designed for long-term weatherproof storage but are ideal for keeping range ammunition organized by caliber, separating reloaded from factory ammunition, and transport to the range. Available in configurations for most common pistol and rifle calibers, plastic ammo boxes keep rounds from rolling loose and allow quick visual identification of caliber at the range. Many competitive shooters use labeled ammo boxes to keep different loads separated for specific applications.

Humidity Control: Desiccant and Dehumidifiers

Moisture is the primary long-term threat to stored ammunition—it can cause primer failures, powder degradation, and case corrosion over time. For ammo stored in sealed metal cans, placing a silica gel desiccant packet inside absorbs residual moisture from the air sealed in with the ammo and prevents condensation during temperature cycling. For ammo stored in safes or cabinets, electric dehumidifier rods maintain low humidity passively without requiring battery or desiccant replacement. Desiccant packets should be regenerated by oven-drying periodically when they become saturated. For serious long-term storage, vacuum-sealing ammo in sealed bags inside metal cans provides maximum protection.

How Long Can Ammunition Be Stored?

Modern centerfire ammunition stored in cool, dry conditions has an essentially indefinite shelf life—properly stored military surplus .30-06 from the 1950s still fires reliably today. Rimfire ammunition is somewhat more sensitive to storage conditions due to its priming system, but quality .22 LR stored in a cool, dry location remains reliably functional for decades. The practical guidance: store ammunition in sealed containers away from moisture, temperature extremes, and direct sunlight; keep desiccant in the storage container; and rotate through older stocks in regular use. Ammunition properly stored at home in a basement or climate-controlled space should outlast any practical need to worry about its shelf life.