Ammunition has a limited shelf life, even when properly stored. However, with the right storage conditions and preparations, most ammo can remain viable for many years or even decades. The key factors impacting ammo longevity include storage temperature, humidity, exposure to oxygen, light, and physical impact. By maintaining cool, dry, and dark storage conditions and hermetically sealing ammo, you can substantially extend its usable life. With prudent planning and proper storage protocols, ammunition can remain usable for the long term.
How Long Can You Store Ammo?
There is no definitive expiration date for ammunition. With optimal storage conditions, most factory ammo has an indefinite shelf life. However, even under good conditions, all ammo will eventually degrade to the point of being unreliable or even dangerous to fire. Actual lifespan depends on the ammo type and your storage practices.
Here are some general guidelines on normal lifespan for common ammunition types:
– Rimfire ammo like .22 LR: Up to 10 years before experiencing misfires or diminished accuracy. Properly stored, rimfire ammo can last much longer.
– Centerfire handgun ammo: At least 10-15 years for reliable function. Can last for decades if stored correctly.
– Centerfire rifle ammo: 15-20+ years before performance drop-off. Proper storage can extend lifespan indefinitely.
– Shotshells: 5-10 years before noticing degraded performance. Fragile compared to other ammo types.
These are just rough timeframes. With optimal storage conditions, most ammo will far outlast these estimates. The most important factor is how you store and handle your ammo day-to-day. Follow proper storage protocols, and even rimfire ammo can stay fresh for 20-30 years or more.
Optimal Storage Conditions
To maximize shelf life, ammunition must be stored in cool, clean, and dry conditions. Here are the ideal storage parameters:
– Temperature: Consistent temps between 55-70°F. Avoid temperature swings.
– Humidity: Maintain below 60% relative humidity. The dryer, the better.
– Light exposure: No direct sunlight or bright light. Store in dark places.
– Oxygen: Exclude oxygen exposure with airtight cases or packaging.
– Physical impact: Avoid drops, shocks, and vibrations during handling and storage.
– Contamination: Keep storage areas clean. Prevent contact with oils, solvents, etc.
Any major deviations from these guidelines will result in accelerated deterioration. For example, excess moisture causes corrosion, oxygen degrades propellants, and heat breaks down chemical bonds in primers. By controlling your storage environment, you can keep ammunition fresh for decades.
Ammo Storage Tips
Here are some best practices for storing ammo for maximum longevity:
– Use airtight containers like ammo cans to seal out moisture and oxygen. Apply anti-corrosion compounds if storing for very long durations.
– Vacuum seal boxes of ammo in Mylar bags with desiccant packs to remove oxygen and humidity. Re-vacuum seal after opening.
– Store ammo cans in a cool, dry room like a basement, closet, or gun safe. Avoid attics, garages, and sheds prone to extreme temps.
– Keep ammo off concrete floors, especially in basements. Use wooden shelves or pallets for airflow underneath.
– Inspect stored ammo at least once per year. Check for signs of corrosion, swelling casings, or loose primer pockets.
– Avoid exposing ammo to solvents, oils, or cleaning chemicals. Store ammunition separately from firearms.
– Rotate stock by shooting your oldest ammo first and replacing it with fresh boxes. This prevents aging ammo from sitting indefinitely.
– Dispose of any ammunition showing clear signs of deterioration like discoloration or powder leaking from casings. Better to lose a few rounds than risk a misfire.
Following these guidelines will maximize the usable lifespan of your ammunition. Just be sure to routinely shoot and cycle out your oldest stock before it has a chance to go bad. With prudent storage methods, most ammo will outlive the guns you shoot it from!
Signs of Deteriorating Ammunition
When storing ammo long-term, routinely check it for any signs of aging and deterioration. Here are some telltale indicators that ammo needs to be disposed of:
– Discolored cases: Once shiny brass casings will tarnish and darken from corrosion over time. This can influence functioning.
– Swollen or split cases: Excess moisture causes metal cases to swell and split at the seams, compromising the ammunition.
– Loose primer pockets: Primers can loosen over time, causing misfires or even ruptured casings.
– Powder leaking from cases: This is a sign propellants have broken down and destabilized. The ammo is no longer reliable or safe.
– Crystallized powder: With certain propellants, moisture causes powder to crystallize inside cartridges, altering burn rates.
– Deformed bullets: Bullets can shift position or become deformed under pressure and impact during long storage.
– Disintegrating seals: Gaskets and seals on boxes or cans can dry out and peel away, compromising moisture protection.
– Rust on ammo: Surface rust isn’t dangerous, but indicates humidity issues. More severe internal rust can cause failures.
Always inspect ammo before shooting it after prolonged storage. Discarding suspect rounds is better than risking misfires or malfunctions.
Storing Rimfire vs. Centerfire Ammo
Rimfire ammo like .22 LR is inherently less stable than centerfire rounds. The priming compound inside rimfire cartridges is more vulnerable to humidity, temperature changes, oils, and other contamination. As such, rimfire ammo has a shorter shelf life of around 5-10 years when properly stored.
Centerfire ammo uses more resilient pressure-sensitive chemical primers. Provided you control humidity and oxygen exposure, centerfire rounds can last for decades without issue. Centerfire ammo also better withstands minor handling knocks compared to fragile rimfire cartridges.
For maximum freshness, store rimfire and centerfire ammo separately using the guidelines above. Some specific tips for storing rimfire:
– Discard rimfire ammo after 10 years, maximum. Small Game cartridges like .22 LR just don’t stay viable as long.
– Keep rimfire storage temperatures even cooler, around 50°F. Minimize temperature fluctuations.
– Inspect rimfire rounds more frequently – at least twice per year if possible.
– Avoid packaging rimfire ammo in sealed bags for very long durations. Allow them to “breathe” a bit.
– Be extra vigilant about keeping rimfire ammo away from solvents, oils, and humidity. It’s more susceptible to contamination issues.
Aside from separating storage, the same principles apply. Just take extra care with temperature regulation and sealing for finicky rimfire ammo.
Storing Shotshells vs. Metallic Cartridges
Shotgun shells also have a shorter usable lifespan than centerfire rifle or pistol rounds – around 5-10 years with proper storage. The paper hulls and plastic capsules are more permeable than metallic cartridges.
Similar to rimfire ammo, shotshells are also vulnerable to humidity issues over time. The propellant powder can absorb moisture and break down. Plastic hulls and caps also become brittle when stored for too long.
Here are some ammo storage tips specific to shotshells:
– Inspect hulls regularly for cracking or brittleness. Discard any suspect shells.
– Vacuum seal shotshells in small batches intended for short term use. Don’t keep them sealed indefinitely.
– Store shells loosely in boxes, rather than packing ammo cans to the brim. Allow space for airflow.
– Absorb residual moisture by adding desiccant packs inside storage containers. Replace frequently.
– Keep shotguns shells cooler rather than warmer. Around 60°F is ideal.
– Discard and replace shotshells every 5 years as a general rule, sooner if you observe issues.
The shelf life of shotshells pales in comparison to modern centerfire cartridges. But you can still get 10 years or more of usability with careful storage practices. Just be extra diligent about inspecting shells and monitoring moisture levels.
Improving Ammo Longevity
You can further extend the usable life of your ammunition through these proactive measures:
Vacuum Sealing
Vacuum seal cartons or cases of ammo in layers of Mylar bags with oxygen absorbers. This displaces moisture and prevents corrosion for decades. Re-seal bags whenever accessing ammo.
Humidity Control
Use large dehumidifiers and moisture absorber packs in storage areas. Maintain relative humidity under 45% for longest ammo life.
Cool Storage Temperatures
Store ammo in naturally cool places like basements or underground shelters rather than hot attics and sheds.
Ammo Cans & Military Surplus Cases
Metal ammo cans provide an airtight protective seals if gaskets are intact. Or use military surplus ammo boxes – these were made to preserve ammunition for decades.
Cosmoline and other Sealants
Coat cartridges in Cosmoline grease or other anti-corrosion sealants for long-term storage. Provides an extra layer of moisture protection.
Inventory Management
Label ammo boxes by date and rotate stock to use up older ammunition first. Keep detailed records of your supplies and storage conditions.
Periodic Inspection
Examine a sample of stored ammunition at least annually. Check cases, powder, primers for any deterioration. Dispose of suspect rounds.
With diligence and proper storage methods, ammunition can remain viable and reliable for multiple generations.
Emergency Ammo Storage Considerations
For preppers storing ammunition for emergency situations like disasters or SHTF events, maximize shelf life by:
– Investing in quality ammunition from reputable manufacturers. Mil-spec rounds hold up better.
– Storing ammo in underground caches or temperature-controlled rooms rather than surface buildings.
– Vacuum sealing in Mylar bags with oxygen absorbers and desiccants for waterproof and airtight storage.
– Placing ammo cans in coolers filled with foam insulation if underground storage isn’t possible.
– Burying ammo on your property in PVC pipes with end caps. Make sure to waterproof and pad ammo inside.
– Limiting bulk ammo buys. Rotate stock by shooting the oldest ammo and replacing with fresh production.
– Keeping a shooter’s “ready stash” of go-to ammunition separate from your deep storage reserve.
– Testing a sample of ammo every 1-2 years for functionality. Dispose of any degraded rounds.
With smart storage practices, it’s realistic to stockpile ammunition for doomsday prepping that will remain serviceable for 20-50 years, if not longer. Just take care to isolate your ammo caches from moisture, oxygen, temperature swings, and physical impact.
Disposing of Bad or Old Ammo
If you have old ammunition showing clear signs of deterioration, don’t just throw it in the trash where it poses a fire and safety hazard. You must responsibly dispose of old ammo. Here are some disposal options:
Contact local law enforcement – Many police and sheriff departments will safely dispose of small amounts of degraded ammo at no charge. Call ahead to inquire about programs in your jurisdiction.
Donate to local firing ranges – Some commercial shooting ranges will accept donations of old ammunition for proper disposal. Never abandon ammo without permission, however.
Ship to a hazardous waste center – As a last resort, you can ship unusable ammunition via approved hazmat carriers to licensed waste management facilities. This entails filling out paperwork and costs money.
Tie out for wildlife – In rural areas, you can tie out old rimfire ammo far from dwellings to dispose of it safely via natural deterioration. Don’t do this with centerfire rounds.
Contact the manufacturer – Some ammo makers like Winchester and Federal will advise you how to return and dispose of defective or unsafe ammunition they produced. Call their customer service lines for guidance.
Disposing of ammunition improperly can be a threat to people’s safety and carries legal consequences in many areas. Do the right thing and seek responsible disposal methods like those above for any rounds that have outlived their shelf life in your stocks.
Key Takeaways on Storing Ammunition Long-Term
Here are some key tips on storing ammo for maximum shelf life:
– With ideal storage, ammunition lasts for decades or longer. Most has an indefinite lifespan.
– Moisture, heat, light, and oxygen exposure accelerate deterioration. Keep ammo in a dark, dry, cool environment.
– Centerfire ammo lasts longer than rimfire and shotshells. But rimfire can still last 10+ years with proper care.
– Inspect stored ammo regularly for any signs of corrosion, discoloration or damage.
– Avoid cross-contaminating ammo with solvents, oils, etc. Store it separately from firearms.
– Consider vacuum sealing in Mylar bags to create an airtight and waterproof seal.
– Cycle older ammo to the front of your stocks by shooting it first and replacing with new production.
– Dispose of unsafe, damaged, or degraded ammo properly through law enforcement, firing ranges, or hazardous waste channels. Never just discard it.
– With prudent storage practices, most ammunition will remain viable longer than the lifetime of the guns that fire it.
Storing ammunition isn’t complex. Just keep it sealed, organized, and under optimal temperature and humidity conditions. By properly caring for your ammo supply, it will be there providing reliable firepower when you need it for decades to come.
Conclusion
Ammunition is inherently stable and long-lasting, but it must be stored properly to maximize shelf life. By keeping ammunition cool, clean, dry, and sealed in an oxygen-free environment, most types can last for many decades, if not generations. Rimfire and shotshells have shorter lifespans of 5-10 years, but can still last much longer with careful storage. The key is to control temperature, humidity, light, and physical impact. With smart storage practices, you can amass stockpiles of ammunition that will remain viable and reliable long into the future, providing you always cycle out older ammo and replenish with new production. Just be sure to responsibly dispose of any rounds showing clear signs of deterioration.