So here's a question for long-term storage of ammo in regards to powder going bad.
Since this powder went bad for Walkalong when he did not expect it, how will we know if powder goes bad inside loaded ammo?
Half of all the surplus IMR 4895 I purchased went bad.
The first lot of 16 lbs, I used up eight pounds quickly. The last eight pounds of the first lot sat around. When I opened the bottle top, it smelled bitter. Red dust flew around.
I gave it to a machine gunner guy. He put it in the laundry room. The bottle got a piece of laundry over it and over night acid gas from the bottle ate holes in the laundry. That freaked my friend and he poured the stuff out over the lawn.
Since then I have had other lots of surplus 4895 powder go bad but in the case. I found green corrosion on the bottom of the bullets and cracked case necks.
First indications that I had a problem were that I had a lot of split case necks on fired cartridges. Then case necks started to crack on unfired ammunition. When I pulled bullets, I smelt nothing, in the case or in the bottle, but I found green corrosion on the bottom of bullets. I believe that nitric acid was weakening the work hardened areas of the case, and causing corrosion on the bottom of the bullets.
Incidentally, the powder shot exceptionally well in cases that did not have case neck cracks. I shot some exceptional scores with the stuff at 600 yards with 168 Match bullets. I had "funny" retorts on some rounds. I discussed this with a Navy Energics expert, and he told me as the surface of gun powder changes, burn rates are affected.
As double based powders detoriate they become surface rich in nitro gylcerine even though the total energy content of the powder is being reduced. This can cause pressure spikes.
This specialist explained that powder deteriorates from the day it leaves the factory. The nitrocellulose and nitro glycerin want to combine to form a lower energy molecule. Nitric acid gas is released in the chemical reaction. The rate of combination is directly related to temperature. The higher the temperature the faster the reaction. Powder contains stabilizers. The Navy samples its powders and propellants. If the powder is outgassing nitric gas (as determined by a paper that changes color (Methly Violet test, or Talliani test)), the stuff is tested to see how much stabilizer is left. If the amount is less than or equal to 20%, the lot is scrapped.
The Army does it different. The Army scraps small arms powders by time. Double based powders and ammunition are scrapped at 20 years, single based 45 years.
I was told that when enough nitric acid is released, the powder will spontaneously combust. The expert diagramed the chemical reaction and drew arrows for hot spots. Hot spots develop in the powder as energy is released. Since the US Military is extremely scandal sensitive, they won’t tell anyone that any of their big bunkers have blown up, but they have. Ammunition depots go Kaboom all the time due to old ammunition spontaneously combusting. You can Google this and find incident reports in the literature. But you won’t find mention of some of the American ammunition incidents that this expert investigated. We Googled one incident he wrote a report on and found nothing in the public domain.
I found this on the web: “
Seven propellant autoignition incidents, some involving 100,000 pounds or more of powder, occurred at Army installations in the 1980s and 1990s. Although it has been 10 years since the last accident, constant vigilance is required.”
Did you ever hear of any of these? I have not either!
Government Rule #2: Minimize Scandal
But there are examples of depots going Kaboom on the web, even if they are not in the US.
http://www.liveleak.com/view?i=13c_1205681217
The expert suggested that it is likely that surplus military powders are not on the market anymore due to liability issues. The stuff was scrapped because the military decided it was not safe to keep around anymore.
If the powder has turned red, or smells like acid, it is way beyond its safe limits.
I talked to Alliant powders. They told me that if the plating inside the old cans is has rust spots, the powder is doing that, and the powder should be dumped.
For this reason, I do not think it is advisable to mix old powders with new. Why have the whole lot go bad?
Extra reading for those who are interested:
www.dtic.mil/dticasd/sbir/sbir031/n154.doc
http://www.almc.army.mil/alog/issues/JulAug08/propellant_stab_eq.html