Armory Sponsor
Posted: 1/21/2013 4:52:50 PM EDT
|
Lets discuss smokeless powder deteriation.
Basically if the can is rusted inside, and it smells really bad it may have deteriated. And most likely should not be used. I got that much, but no-one explains what happens to the powder. What causes this? exposure to moisture? Anyone know what effect this has on the powder? Does it lose "strength" or become less stable? I have reloaded for 25 years and never thought about this, but I recently opened a can of powder from the 70's and it just looked funny, Had some reddish dust mixed in it. I assume rust from the inside of the can. That is when I started looking for answers. google didn't turn up much. |
|
Smokeless powder is a chemical compound that is designed to be combustible. It should produce great amounts of gas and pushing pressure. It should also be non reactive until initiated by a primer or primer/booster.
A chemical compound like this is degrading from the moment that it is made. As it degrades, it produces heat. As the heat builds up, it reaches a point that the propellant will spontaneously combust or (if you're lucky), "rot" away into a useless powder. To protect the propellant as long as possible, "stabilizers" are included in the chemical mix. The problem compounds are acids that are made when the propellant degrades. As the acids accumulate, they make heat and degradation accelerates. Stabilizers (Calcium Carbonate is a very popular one) are like Tums for powder. They soak up the acids and chemically tie them up so they won't cause further degradation. Always give an opened container of propellant the "Smell Test" when you open it. A solvent smell is normal (Ether for IMR and Acetone for Reloder). These are the solvents used to make the propellant. If you get an acidic or pungent smell, spread some or all of the propellant out on a clean white surface and inspect it for condition. The red dust you mentioned is a sign of deterioration. If the granules crumble easily, that's another sign that somethings not right. If there are rust particles from the inside of the metal can, the propellant is attacking the metal and that propellant is bad. If it doesn't smell or look right, dispose of it and get a new container. Propellant is inexpensive enough that there is no reason to try to save it forever. |
|
I smelled the can, smelled alright.
The bottom two inches was red with flakes. Unfortunately I had already loaded about 100 - 308 rounds. Better safe then sorry so. I spent the first hour of work pulling bullets today. 
I had a half red solo cup full of powder, that has a reddish tint. Hopefully it will make good fertilizer. |
|
The nitrocellulose loses its nitro groups which are acidic, causing corrosion of the can. This lets in more air which causes further deterioration. The red vapors are nitrogen dioxide, very acidic. Age and heat cause it. Not water. Most powder contains preservatives like diphenylamine which are not only anti-oxidants but also increase the pH, stabilizing any free nitrogen dioxide. Decomposing powder can burn faster so you shouldn't use it. If loaded, it will rapidly destroy the brass case which could pose a danger. |
|
Quoted:
I have reloaded for 25 years and never thought about this, but I recently opened a can of powder from the 70's and it just looked funny, Had some reddish dust mixed in it. I assume rust from the inside of the can. My guess is it's an IMR powder. I've only seen this red dust from deteriorating IMR powder. Something happens and it leaches this red dust. I've fired with no problems. YMMV |
Armory Sponsor