Print Page | Close Window

Dangers with Deteriorating Powder

Printed From:
Category: Reloading
Forum Name: Reloading .303 British
Forum Description: accepts NO responsibility for any loads that may be used by persons reading this forum. USE CAUTION WHEN TRYING ANY NEW LOADS!!! ANY DATA DEEMED UNSAFE WILL BE REMOVED!!!
Printed Date: December 08 2023 at 5:07am
Software Version: Web Wiz Forums 12.04 -

Topic: Dangers with Deteriorating Powder
Posted By: britrifles
Subject: Dangers with Deteriorating Powder
Date Posted: October 12 2022 at 4:05pm
About 25 years ago, I took all of my Dad’s reloading powder home with me, there was quite a bit of it.  All of that powder was made in the 1960’s, or even earlier.  It was stored in good conditions, however, some of that powder he got from one of his friends, and who knows how long he had it and how old it was. He began reloading in the late 1940’s. 

Well, I thought I had gone thru all this powder and burned most of it up.  I was wrong.  I had moved it all out of my powder cabinet, opened each can to check the condition, and kept a few of the cans putting them on a shelf in my loading room. The rest I burned in the fire pit.  

I went looking yesterday to see if I had kept any of the IMR SR 4759.  What I found was a swollen can of Norma powder with a thick layer of red dust on the shelf all around the powder can.  I took it outside and here’s what it looked like.

The sides were bulged and burst open.  Took the top off and this is what I saw:

Complete decomposition of the stabilizer.  I’m very lucky this did not spontaneously combust from the self heating autocatalytic exothermic reaction.  My house would have burned to the ground. 

I was so sure I opened every can of powder and checked it a few years back.  Perhaps I missed this one, or perhaps the reaction occurred fairly quickly.  

I hate to waste powder, but there is a real danger shooting deteriorated powder.  The powder can become very unstable and result is very large pressure spikes when ignited in a cartridge loaded in a firearm. 

I got really lucky here…

Posted By: Shamu
Date Posted: October 13 2022 at 1:41pm
Definitely one for the "Black Museum" there.Censored

Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)

Posted By: britrifles
Date Posted: October 13 2022 at 6:13pm
I tell you Sham, I dodged a disaster there.  This is a serious hazard.  Lots of documented cases of spontaneous ignition of old powder.  Not to be dismissed. 

Posted By: Shamu
Date Posted: October 14 2022 at 9:27am
I was actually surprised you burnt it! Definitely a case of "light the blue touch paper & retire to a safe distance"!Evil Smile

Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)

Posted By: Honkytonk
Date Posted: October 14 2022 at 10:36am
Good you found it before something bad happened. Lesson for all...

Posted By: Marco1010
Date Posted: October 16 2022 at 6:20pm
I unloaded about 300 rounds of CAC ammo in 308 win. I'm guessing that it had been loaded in the 1960's for use in the army SLR , the cases were good but the powder had gassed and when you pulled the projectiles there was a pop of compressed gas and the powder was wet and oily looking.
It ignited poorly, so I laid it out on a garbage can lid to dry and then set it up to burn off.
I ignited it with some cannon fuse, so I could get well away.  i had a column of flame about 25 feet high and the radiant heat from 30 feet away was intense. any closer any I would have had no eyebrows.
Burned for about 5 seconds all up.  I suppose the nitroglycerine had started to separate out.
Glad i never fired any of the cartridges.

Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.04 -
Copyright ©2001-2021 Web Wiz Ltd. -