When milsurp ammo goes bad.........

[nola jack]

Damn!

[desi23]

Smokeless powder certainly does deteriorate over time and storage conditions often play a large part in this. The quality and chemical makeup of the powder is also important. Certain types of powders seem to be more vulnerable to breakdown, single base extruded powders are the ones I have encountered the most. Historically, double base powders have a good record for durability, Hecules powder company manuals used to refer to test lots of their early powders that they had kept from the early 1900's that were still good. Ball powders were developed in the 1930's by Winchester/Western as a way to salvage deteriorated single base powder left over from WW I by re-blending it and adding nitroglycerin. It worked so well that they went on to develop more types of Ball powder.

Military forces have fairly strict standards for ammunition, largely because ammunition that fails to perform to the highest standard puts their troops and, indeed, the country at risk. Most dispose of ammo at a point where it I still quite useable, well before the projected lifetime of the loads. Some genuinely bad stuff does get out to the commercial market, victims of bad storage, overlooked old stock or was just questionable to start with. Deteriorating powder can corrode the bullet to the case neck, increasing bullet pull and sending pressures sky high. Inspecting ammo for case neck corrosion should be done with any old ammo you obtain, I routinely pull down a couple rounds to check with any lot of old stuff I pick up just to double check for internal corrosion. If it's bad I can still usually salvage the bullets for reloading.

Suplus ammo can be great, cheap shooting but like anything else there are risks. Inspect carefully before use, if in doubt tear it down and check further.

[SlamFire1]

I know Hercules has a canister of powder, that they have had under water, since 1900 or earlier. I have reviewed the Army Ordnance Magazine from the late 20’s to the 40’s and found articles on gunpowder stability. Exposure to water is bad for several reasons, one of which water dissolves chemicals out of the gunpowder gelatin. The paper I read showed micro cracks in the powder grain. Hercules did not conduct any lifetime tests outside of the water and I highly suspect that powder deterioration of their sample would accelerate once out of the water.



In 1936 Hercules was bragging about Bullseye lasting 25 years. It is obvious to me that if they were bragging about their double based powder lasting 25 years then the lifetime of powder was relatively short prior to WW2. Perhaps better controls in industrial processes have extended the shelf life of gunpowder, but in 1931, the storage lifetime of smokeless powders was considered to be 20 years or less:

Army Ordnance Magazine, June 1931, page 445 says:

“Smokeless powder constitutes one of the greatest hazards from a storage standpoint, due to the fact that it is subject to deterioration and at the best cannot be expected to have a life greater than about twenty years…….Master samples of all lots of smokeless powder are under constant observation in the laboratories at Picatinny Arsenal. Should any of these samples indicate rapid deterioration, notification is given at once, and steps are taken to use this deteriorating material within a very short period, if possible, or else withdraw it from service.”

A major consideration with old gunpowder is auto combustion. Misfire and malfunction rates are a real concern and I believe one criteria for flushing out ammunition out of inventory, but the greatest concern, because of the damage caused when an ammunition dump explodes, is auto combustion.

Ammunition Surveillance Procedures SB 742-1

https://acc.dau.mil/adl/en-US/238111...0AIN47-13A.pdf

Chapter 13 Propellant and Propelling Charges

page 13-1

WARNING

Nitrocellulose-based propellant can become thermally unstable as the age. The normal aging process of the propellants involves deterioration of the nitrocellulose with an accompanying generation of heat. At some point, the propellant may reach a state where heat is generated faster than it can be dissipated. The accumulation of heat can lead to combustion (autoignition). Chemical stabilizers are added to propellants to slow the aging process. In time, the stabilizer levels will drop to a point where the remaining effective stabilizer (RES) is not sufficient to prevent an accelerating rate of decomposition. When this point is reached, the propellant may autoigniet, with possible catastrophic results to property and life. Monitoring the stability level of each propellant lot is essential for continued safe storage.

Page 13-5 , Table 13.2 Propellant Stability Codes.

Stability Category A 0.30 or more Percent Effective Stabilizer
Acceptable stabilizer loss: safe for continued storage

C 0.29-0.20 Percent Effective Stabilizer
Significant stabilizer loss. Lot does not represent an immediate hazard, but is approaching a potentially hazardous stability condition. Loss of stabilizer does adversely affect function in an uploaded configuration. Disposition instructions will be furnished by NAR. All stability category “C” assests on the installation must be reported in writing…
One year after becoming stability category “C” a sample of the bulk propellant lot or the bulk-packed component lot will be retested. If the lot has not deteriorated to category “D”, it will be retested each year until it has been expended, or it has deteriorated to category “D”, at which point it will be demilitarized within 60 days.

D Less than 0.20 Percent Effective Stabilizer
Unacceptable stabilizer loss. Lots identified as stability category “D” present a potential safety hazard and are unsafe for continued storage as bulk, bulk-packed components , or as separate loading propellant chargers. Bulk propellant, bulk –packed components and separate loading propelling charges will be demilitarized within 60 days after notification of category “D” status.

There were huge stockpiles of old ammunition in eastern Europe when Communism collapsed. There was no money to fund stockpile surveillance activities and within a couple of decades old ammo dumps started exploding.

Albanian Depot Explosion
http://www.youtube.com/watch?v=j8UK6b2y3kQ

http://www.youtube.com/watch?v=oYNZCwkKisc

[hendere]

I collect cartridges, mostly military. For what it's worth, I've torn down quite a few that were going bad. Sometimes quickly expanding holes with green slime coming out. But I don't think I've ever actually seen powder that looked bad. Maybe a few green flakes, but nothing that I would say was obviously not from the brass. I'm sure it's mostly always the powder deteriorating, but it just never looks bad. As far as hot and humid storage goes, it's very common to see German and Finnish stuff going bad. And I've had a fair amount of American stuff also. Powder just goes bad sometimes.....