Corrosion in long term storage of BP rounds.

[GregLaROCHE]

I’ve found that BP can sure be corrosive even before it’s been burned (fired).

I’ve been wondering what happens to brass loaded with BP after a few years. Being more or less air tight, is the corrosion stopped. Can the power start working on the primer and cause problems?

I’ve always shot all of mine soon after loading, but the other day found one that was a couple of years old and have been wondering if I should pull it apart to protect the brass. Maybe the simplest thing is just to shoot it. Anyway does any significant corrosion take place on the inside of the case?

[LynC2]

I've pulled down a number of cartridges made in the 1880's and never saw any corrosion of the brass cases from the powder. However the grease cookie under the paper patch bullet had deteriorated and some cases were corroded at the base of the bullet. BTW, the powder was excellent when I fired some in my rifle.

[M-Tecs]

I’ve found that BP can sure be corrosive even before it’s been burned (fired).

I was given some 1860's era BP that had been stored in the original wooden barrel. I didn't not see the wooden barrel but the powder looked and shot normal. Back in the 70's I fired some BP with the a 1890's date. A couple failed to fire due to the primer. When they fired POI and grouping was good. I don't remember any noticeable corrosion on the cases.

What type of corrosion were you seeing?

[GregLaROCHE]

I wasn’t seeing any corrosion on the cases, except if they had been fired and I didn’t get them in water soon enough. The corrosion by unburied powder I’ve experienced is in my powder measure, if I don’t empty all powder out after using it. My basement where I reload is a little on the humid side, and that doesn’t help, but I never had that problem with smokeless.

[M-Tecs]

https://www.chuckhawks.com/problems_...rn%20as%20fast.

The Problems of Black Powder

By Randy Wakeman

A problem associated with black powder is its hygroscopicity. Black powder absorbs about 1.5 weight percent moisture under 75 percent relative humidity at a temperature of 21.1.degrees C. (70.degrees F.) over a period of 24 hours.

[john.k]

I read a military report on faulty blackpowder(big guns still use blackpowder today),and the conclusion was that the problem was caused by degradation of the blackpowder ,caused by polluted water used in the damping down phase of manufacture ,and also identified the presence of sodium nitrate ,which IIRC ,is a thousand times more hygroscopic than potassium nitrate ......seems pure potassium blackpowder isnt hygroscopic ....that fault is introduced by sodium impurity.

[M-Tecs]

I am not an expert on Artillery but everything I have read indicates that Blackpowder' s only use in modern big guns is a kicker charge on the bag guns to insure proper ignition. I do remember reading about Winchester having million and million of gallons of WWI surplus artillery powder held in a liquid slurry that they extracted the Nitroglycerin from since it was safer and cheaper to produce than new manufacturer of nitro.

https://www.history.navy.mil/about-u...9/h-029-4.html

“The initial explosion was caused by premature ignition of five bags of smokeless powder contained within the center gun with the breech open. The point of ignition was most probably between the first and second bags. Exhaustive technical tests have ruled out the following possibilities which constitute the most logical inadvertent causes: burning ember, premature primer firing, mechanical failure, friction, electromagnetic spark, propellant instability, and personal procedural error. Although deficiencies in training documentation, weapons handling procedures, and adherence to safety procedures were found within the weapons department, the exhaustive tests and duplication of the type of blast that occurred have conclusively demonstrated that these shortcomings did not cause the explosion….

“Confronted with evidence that brought into question a possible wrongful act, the Naval Investigative Service (NIS) conducted an exhaustive investigation into the backgrounds and recent behavior of not only the center gun room personnel but of all relevant USS IOWA crewmembers….

“Additional hard factual evidence such as the position of the projectile/powder rammer and the subsequent delay in retracting the rammer to allow closing the breech provides credibility to the theory that an intentional human act caused the ignition of the powder charge. The critical controlling station within turret II to allow the aforementioned factors to occur was the center gun captain. These factors, when combined with circumstantial evidence associated with the individual manning that gun captain position at that the time of the explosion, strongly suggest that an intentional human act most probably caused the premature ignition.

“The combination of these factors leads me reluctantly to the conclusion that the most likely cause of the explosion was a detonation device, deliberately introduced between the powder bags that were rammed into the breech of the center gun. This caused premature detonation and subsequent disastrous explosions aboard USS IOWA on 19 April 1989, resulting in the deaths of 47 sailors, including GMG2 Clayton Hartwig. I further concur with the investigating officer and subsequent endorsers that the preponderance of evidence supports the theory that the most likely person to have introduced the detonation device was GMG2 Hartwig."

The CNO’s endorsement included discussion of an analysis by the FBI of trace foreign material found in the center gun barrel of Turret 2, which the Navy investigation assessed to be evidence of an electrical igniter/timer of a type that could be purchased at an electronics store. Although the CNO’s letter described the FBI analysis as “inconclusive,” the FBI had actually determined that the elements were not consistent with an electronic igniter, but were probably from the “Break-free” solvent used to help dislodge the projectile from the barrel. In addition, on 28 August 1989 (two days before the CNO’s endorsement), technicians at Naval Weapons Support Center, Crane, confirmed the FBI’s analysis that no electrical timer, batteries, or primer were involved. The Navy’s theory then shifted to the use of a chemical igniter, which was also, much later, disproven.

[LynC2]

I am not an expert on Artillery but everything I have read indicates that Blackpowder' s only use in modern big guns is a kicker charge on the bag guns to insure proper ignition. I do remember reading about Winchester having million and million of gallons of WWI surplus artillery powder held in a liquid slurry that they extracted the Nitroglycerin from since it was safer and cheaper to produce than new manufacturer of nitro.

From everything I've read, the very large artillery pieces used it as a means to ignite the main charge of smokeless as in the 16" naval guns.

[Dan Cash]

Neighbor recently picked up some late 1860s-early 1870s spent .45-70 casings on high hill on his ranch. This ammo was of the Benet internal primer type. It exhibited a black stain or patina on the case interior while the exterior was relatively unstained. Guarantee that stuff has been laying there for more than a week.

Artillery: Even fixed cannon ammo still uses black powder in the primer tube.

[greenjoytj]

I have often wondered if galvanic corrosion would occur inside a cartridge case, caused by having 2 dissimilar metals (lead) touching (brass) each other which would form a battery.

[M-Tecs]

The 50-70 was used from 1866 to 1873 when the 45-70 was adopted. The oldest I have in my collection is 1888.

As to galvanic corrosion copper/brass and lead are low on the scale of metals that suffer from galvanic corrosion issues. Lead copper/brass solder joints don't have galvanic corrosion issues and they have been used in some very harsh environments for hundred of years.

http://www.rmmcia.com/blog/metal-com...anic-corrosion

[john.k]

No water -no galvanic corrosion.....A cartridge sealed from the atmosphere,will not corrode internally.

[greenjoytj]

Citric acid is an ingredient in Crisco shortening. Crisco make up 40% of the Emmerts bullet lube that I make. Maybe the citric acid could have an affect on long term storage of cartridges made with bullets lubed with a lube that contains Crisco.

[freddyp]

Like the other guys here, I have never seen a problem with BP. I had a box of 45LC that were loaded with black powder substitute powders that corroded the brass case. These rounds were loaded with American Pioneer powder. It was loaded in new brass and the bullets were lead bullets with smokeless bullet lube. The box was probably about 5 to 7 years old. I fired a few of the 45LC rounds and had about half of them split down the side after firing. Took a few apart and discovered that the powder had corroded the inside of the case. I have seen this a few times with other ammo loaded with powder that has similar chemistry. Whatever they use to make this type of powder is definitely corrosive to brass over time.

[Japlmg]

Way back when I was a teenager (1960's), I bought a Remington Rolling Block in 43 Spanish for about $13.00.
Soon afterward I bought an entire sealed case of 1000 43 Spanish cartridges (for 2 cents a round), that were manufactured by Winchester with 1892 headstamp date.
Black powder propellent, lead bullets, sealed with lacquer at primer and case mouth; the exposed bullet appears to have been wax coated, as they never formed that white lead oxide film.
Have been shooting them ever since, and still have about 300 left.
Started getting slight hang fires about 30 years ago, but by then the primers were almost 100 years old.
Today about 1 out of 3 is a definite click bang, but they still all go off first try.
I fired about 20 rounds this past winter, and the inside of the cases look like new after cleaning.
Yes, I have reloaded some of the cases, as they were boxer primed, but I suspect they were mercuric primers, as about 50% split at the neck/shoulder upon firing.
Yes, I did aneal them before reloading.

Thus, in my observation, if the case is sealed, black powder has a very long shelf life.

[BombDoc]

Moisture is the problem.. As has been said, dry BP will last almost indefinitely. I have recovered powder from shell fired in the 1880s, and provided the seals are good, it was as good as the day it was made..

I also have some BP 12 bore shotgun cartridges made about fifteen years ago with paper cases. They are all showing green corrosion around the primer pockets, and I am getting very high primer failure rates!

Gunpowder was used almost universally for BL (Breech Loading) artillery that uses a bag charge and a tube for firing. The tube is basically a blank cart that fires burning pellets into the breech through a vent tube. The bag charges have a BP filled pouch at the end of the cart to pick up the flash from the tube and provide even ignition to the propellant charge. QF (Quick firing) guns with a brass case usually have a long perforated primer tube filled with GP running up the length of the case, again to provide reliable ignition. Charge bags are usually stored in sealed bags or containers to control the moisture content.
The 175mm Howitzer had a very long and narrow chamber (over a yard long and about 10" across..) this had a 1 1/2" gunpowder filled polythene tube running down the centre of the charge bags to ensure the whole charge got ignited.

In the last ten years or so there has been a shift away from using gunpowder in gun systems, replacing it with a flaked nitro powder. This is not as easy to ignite, and needs more powerful primers, but seems to be less affected by damp and creates less smoke.

[djryan13]

Gosh... I left BP in my Hornady black powder measure for months (years?). I agree with above. Moisture is a problem. It was caked on. I had to polish it up a bit when I finally started reloading it again. Works great now.

[KCSO]

It all depends on how and where it was stored. I have 1888 FA loads that still look like new inside and out and I have seen the same rounds corroded and unusable. In general if stored in a clean dry environment they will last for at least a hundred years or more. I have kept a cap and ball revolver loaded for up to a year at a time with no corrosion if kept properly. A few years ago for testing Military 45-70 loads I shot a bunch of 1880's loads and actually the dried lube was more problem than the powder or the primers and the cases held up really well, good enough that they were cleaned and reloaded several times with different modern black powder.

[Chill Wills]

Brass reloaded after being fired with BP is another animal altogether. Burned BP is very corrosive and burned smokeless not so much. Fairly important to thoroughly wash/clean BP fired brass. Of course brass that has been fired with mercuric primers, no matter the powder type, needs to be washed/cleaned.

We might be splitting a hair here but I would agree that BP fouling is hydroscopic. From all that I have I have read on the subject BP is not corrosive.

[KCSO]

From 1911 Smokeless 45 Colt ammo... "as soon as possible after firing decap the shells and throw them in water, clean inside with brush or rag". This was due to mercuric primer fouling attacking the brass, much more corrosive than B/P fouling.