ATG: Old Ammunition
Is Old ammunition safe to shoot?
Generally speaking, YES: Old ammunition is safe to shoot. (See below for clarification)
Question: Does gun ammo have an expiration date? I have some shot gun shells and 22 cartridges in a gun locker since 1994. Is the ammo still good?
Answer: Generally speaking, older ammunition is safe to shoot. If a firearm was made after the industrial revolution in the United States, it will have sufficient metallurgical properties to handle any “smokeless powder” ammunition. First and foremost, make sure you are using the proper ammunition. There are a few things that can hinder your “old ammunition”, though, so keep reading.
Old Ammunition does not have an expiration date if stored in optimum conditions.
Now for the specifics on how to determine if Old Ammunition is past its prime:
- Moisture and heat are bad for cartridges; if you’ve stored your old ammunition in damp or extremely hot places the powder may be prematurely rendered useless (see specific notes below)
- Extreme vibration and rough handling can be bad for old ammunition (see below for specific notes)
- Coastal air with salt in it can be bad for ammunition (see below)
- Chemicals in contact with cartridges can be bad for their longevity and safe use (see below)
Old ammunition affected by Moisture:
Moisture in old ammunition is about the most likely perpetrator for damage to the cartridge. The old saying keep your powder dry was important because it alluded to the fact that powder wouldn’t fire when wet; rather it couldn’t be ignited. That saying was referring to blackpowder, but only because of the time period in which the saying was originated. Modern smokeless powder is also susceptible to moisture. Usually the primer is the main culprit for allowing moisture into the ammunition.
Modern high end ammunition uses special double bullet crimps and special sealants over the primer to ensure the chances for moisture to enter are low. The same sealant as used on primers can be used at the case neck for a similar reason. The whole point, is to ensure reliable ignition and so that the ammunition can become old ammunition.
Ammunition affected by heat:
Prolonged exposure to heat can bring the capacity of the primer and the powder to burn/ignite, down to virtually non-existent levels. Rounds have cooked off before in extreme heat conditions, setting the cartridge off; cartridges left to be stored in hot enough conditions (yet not hot enough to cook off the round entirely), will still have a negative effect on the primer and the powder’s ability to burn/ignite in the future.
Old ammunition affected by rough handling:
Something about the jostling of ammunition can de-seat the projectile and cause moisture to enter the cartridge. Additionally, I have talked with helicopter pilots and those who have packed ammunition in backpacks over rough terrain and have been told that powder does not burn consistently and can cause squibb rounds. I have been told it’s because the powder somehow congeals, or sticks together causing bad or slow burns, and low powered rounds. I cannot confirm that this is the case, but I try to avoid such conditions either way.
Old Ammunition affected by salt air:
Salt air can cause corrosion and leaching, allowing moisture and chemical damage to the brass/primer and powder. It can cause old ammunition prematurely.
Old Ammunition affected by chemicals:
Even a bit of cleaning solvent left on or in contact with cartridges can cause the solvent to render the powder ineffective and cause chemical reactions in the materials of the ammunition.
Prematurely Old ammunition as a result of temperature swings or condensation:
Ammunition can become prematurely old by being subjected to extreme cold, or artificially cold environments, including air conditioned cars or buildings. The change from cold environment to warm or hot outside temperatures can cause the powder to become wet from condensation on the cartridge.
The point with ammunition is this: old ammunition may exist, but it doesn’t mean the ammunition is expired. If you suspect there is a concern with moisture (the main reason ammunition “goes bad”) or other factors, shoot the ammunition and wait 10-20 seconds after the rounds do not fire to get them out of the gun. Keep the barrel pointed in a safe direction.
The best way to ensure that ammunition is sound and viable is to preemptively work on storage and attention to conditions, and you can sidestep concerns.
There is such a thing as old ammunition, but with proper storage and environment conditions, it will just be good old ammunition.