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gschwertley
Registered Member
Posts: 1
(10/19/04 12:26 am)
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deterioration of propellants
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I have been reading items in these forums for some time as an observer but have never participated. Recently I was invited to chime in, so will start with this one.
I am now 54 years old and have been interesting in guns and shooting since 1964. I have been an active reloader/handloader for over 20 years. Maybe I have been fortunate so far, but only this year have I come across the problem outlined below and it has come to my attention twice in the past few months.
I am referring to deterioration of small arms propellants after loading. My first experience was with some old .270 Winchester rounds given to me at a gun show. The cases were corroded and there was moisture present inside the plastic box. I took them with the idea that the bullets might be salvagable. This did not work out, as the interiors of the cases were highly corroded. The small diameter of the bullet coupled with the rather long inside neck surface held the bullets fast with the added element of corrosion. The bullet bases were damaged by corrosion as well.
The real story is with the powder. It was identified as "old 4831", no reference to IMR or Hodgdon. Much of the "old" 4831, at least from Hodgdon, was salvaged propellant from surplus military use.
The powder in these cases had agglomerated, that is, was sticking together as a mass, in most cases. It was suspended in a liquid that in some cartridges had eaten through the brass case and leaked out. In other examples, the liquid had leaked past the primer.
The second experience I had recently with some 7.92x57 German surplus rifle ammunition. This was headstamped P154 (Polte Werk Gruneberg), dated 1935.
This ammo I had purchased back in 1972 or 73; I had fired all of it off previously and had retained one 15 round quantity in the original paper container. It has been in a sealed GI metal ammo can for over 30 years. I had not examined in for at least 10 years, but I know it wasn't corroded when last looked at it.
When I happened to examine these cartridges yesterday, I was interested to see that many of them had dried green verdigris on the outside and at least one had a clear liquid leaking from it. I pulled the bullets from all 15 pieces and the interiors were highly corroded. In about half of them, the powder (European cut sheet powder) had agglomerated; the others had the powder still somewhat in a loose configuration.
Not being a chemist or a scientist of any kind, I can only speculate the the nitric acid in these two single-base powders had degraded somehow and was starting to liquify, leaching out of the cellulose.
When the powder degrades in this manner and agglomerates inside the cartridge case, it seems to me that a dangerous situation has presented itself. If such a cartridge is attempted to be fired and the primer is still viable, and if this agglomerated powder ignites as a mass it cannot blow down the barrel in burning granules as it normally would. It can only remain in the chamber and burn in situ. It does not take much more imagination to visualize further possiblilities. As I related earlier, I have been engaged in shooting activities for some time, and I am glad to say that so far I have done so without blowing up a weapon or myself.
So, can anyone contribute to this, particularly as to knowledge of this being a manufacturing defect in propellants, or is it a storage issue? Any other comments?
Kar98AZfan
Moderator host
Posts: 288
(10/19/04 5:07 am)
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Re: deterioration of propellants
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You are indeed right about the breakdown of the nitroglycerin
in the powder.Mostly what I've read points to poor storage &
relaxed wartime quality control. I've attempted to fire rounds
that had agglomerated (not on purpose) and none would
fire,probably because the nitro has broken down into its
oringinal parts. I'm still using a batch of surplus 4831 thats
still in excellent shape,so breakdown is apparently not a given.Great info on the 8x56R by the way.-TR
No man's life,liberty or property are safe when the legislature is in session-Mark Twain (1866)
Edited by: Kar98AZfan at: 10/19/04 5:08 am
TNGunsmoke
Moderator host
Posts: 1438
(10/19/04 7:55 am)
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Re: deterioration of propellants
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Sounds like a reasonable explanation to me. I've never seen it, but I've only been loading for a couple of years. Great info and Welcome to the forums.
Come visit us and discuss the Weapons of Yesterday Yesterdays Weapons Forums
mikmarjon
Moderator host
Posts: 1726
(10/26/04 9:44 pm)
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Re: deterioration of propellants
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I've seen some Jap rounds that did this from obvious poor storage,and even had some given to me,the cases were in such bad shape that I just threw them away.I wondered what was hapening,now I know.Thanks a bunch for you astute observations.
mike
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