I woke up in the middle of the night last week thinking about how my ammo is stored. Thankfully my worries were put to rest after referring back to this article by Kyle Wintersteen. On Saturday evening around six we lost power from a severe thunderstorm. Our generator kicked on but it doesn’t provide enough juice to light up the whole house. That event provided the kick in the you-know-what to take proper inventory of flashlights and batteries. It also was an unexpected opportunity to review emergency situations with the family.
Modern, factory-loaded rounds are designed to function reliably in conditions ranging from the arctic to the tropics. Therefore as long as you prevent exposure to extreme heat, high humidity and temperature fluctuations, your ammunition can be expected to last 10 years.
According to Rick Patterson, Managing Director of SAAMI, “In fact as long as your ammunition is stored at normal room temperatures with low humidity, it can function reliably for decades.”
It takes more than just a warm day to detrimentally impact ammunition—SAAMI believes the breakdown begins around 150 degrees Fahrenheit. There are very few environments where stored ammo can reach those extremes, but the trunk of a vehicle is one of them.
“Definitely avoid storing ammunition in a car on a hot sunny day—that’s probably the single most likely scenario that could cause problems for the average shooter,” Patterson explained. “With extremely high temperatures, you get rapid degradation of the ammunition components. The case and bullets are relatively inert in terms of temperature, but the chemical properties of the gunpowder and priming mixture can be affected … Over time, you’ll see a drop in performance, perhaps to the point of going click rather than bang.”
Theoretically, extreme cold could eventually impact ammunition, but it isn’t worth your concern. High heat kills otherwise good ammo, and that’s the primary thing to avoid in regards to temperature. Rapid fluctuations could, however, also prove detrimental over time. So if you’re among the many Americans storing shells in garages, perhaps you should reconsider.
“It’s easy to forget just how much conditions vary through the year, let alone over the course of many years,” said Tim Brandt, Media Relations Manager for Federal Premium Ammunition. “Here in Minnesota it can hit 100 degrees in the summer and negative 30 in the winter.”
Wintersteen goes on to explain the dangers of humidity to ammunition, and I encourage you to read his advice here. While you’re checking on your ammo storage, do a quick review of the ways you store other supplies. Be sure to first consider your water storage plan.
