General black powder question


How stable is black powder? If I have cartridges dating back to 1860’s, do I need to be concerned with spontaneous ignition? What happens if one shakes them?


Vlad–Black powder inside a cartridge is very stable and safe to handle. Shake it all you want with no problem. For one thing, most black powder charges are compressed so they won’t shake anyway. While black powder is not a problem, early smokeless powders from the 1890’s-1915 or so are.
These powders are not dangeriious to handle, but they breakdown and form an acid inside the case that eats through the brass, This forms the dreaded “Blue Green Slime” you often see at the casemouth of cartridges of this era. Nothing can be done except pull the bullet, scrub out the case and replace the powder with an inert substance like sand. Unfortunatelly, most the time you don’t know theres a problem until you pick up your cartridge and the bullet falls out because the neck has cracked or the neck is completely eaten away.


Unfortunately, I am very familiar with blue-green slime. Would you recommend removal of gun powder? How does that affect the collectible value? How is bullet removal done? Is it safe?


Vlad–Removing of the powder is the ONLY way to save a case that has started to show the slime. It will not get better, only worse. Some collectors even feel that ALL cartridges loaded with the early smokeless powders (about 1895-1915) should have the powder removed even if they do not show signs of beakdown because it is just a matter of time before they do. Most cartridges made after about 1915 will not, as a rule, be a problem as the formulation of the powders used after that was changed.

As to value, I guess that is a personal choice. I would rather have a cartridge filled with sand than have it destroyed. I have had a number of valuable 1900 era rounds ruined. But, if I am buying a cartridge of this era, I would rather be paying for a factory original than a modified round.

As for the safe way to remove the bullet, the use of an inertia bullet hammer is the best, but be ABSOLUTE positive that the round is not an explosive or incendiary of any type.

I knew a guy who tried to remove a 7.7 Japanese Explosive bullet this way. He removed 2 fingers instead.
Many incendiary rounds have a soldered hole in the side of the bullet below the case mouth. If the solder has come loose for some reason, when you pop the bullet out you can have an instant fire when the phosphorous comes into contact with air.


I would add to the above comments that I have what would be a real gem of a US military round from 1945 (original pre-T65 experimental .300 Savage proof) which showed some of the corrosion pus and compromise of brass integrity when I bought it. Taking the “better clean it up ASAP” approach, I put it in an inertia hammer within 72 hours of acquisition. The first tap, and I had two pieces . . . problem was / is that one of those pieces consisted not only of the bullet, but also the neck and most of the shoulder. At some point, I guess I will find some way to put the two together by filling the cavities with an epoxy of some kind and then gluing.

I still don’t know if there would have been any sort of chemical bath I could have used to ease counter-act the corrosion or ease the bullet out of the neck leaving the case intact. If I had things to do over again, I would have drilled the case and removed the degraded powder through the opening, likely resorting to some chemicals toward the last.

So . . . the bottom line is . . . be [u]VERY[/u] circumspect about breaking down any specimens showing signs of corrosion as they may in fact be very fragile internally.



I too have had quite a few World War 2 US cartridges break up after internal corrosion, mainly .30-06. I was able to snap one A.P. round in two, just below the shoulder, with my fingers, no inertia hammer! I have not yet seen similar problems with the WRA .303" ammo sent over here. There is still a lot of this stuff around but I would never recommend shooting it as the primers are very agressively corrosive (you can almost hear your rifle rusting as you walk away from the firing point).



What will happen if one fires a round with “blue-green slime” corrosion? Will it work normally or blow up?



Fortunately, God made firearms with a big margin of safety and the most likely result will be a case seperation. Of course, the closer to the head that the seperation occurs the more of that safety margin is compromised.



sksvlad - the internal ballistics intend for the pressure curve to rise as the projectile passes down the bore, ideally with the production of the propelling gas ceasing at the point the projectile exits the bore (+/-). If the projectile is delayed in its release from the casing or, far worse, remains mired in it, the pressure will seek grow in the chamber, possibly (very possibly in the latter instance) exceeding the design parameters of the firearm. If it is a mild load in a strong action, the gases will escape through the action in time (very short time measured in milliseconds, but long compared to the normal sequence of events), delivering hot gases and possibly small fragments from the escape routes. Hotter loads will have more dramatic, possibly even lethal, results with actions rendered useless, etc. I suppose there are formulas somewhere which can predict this to some degree, but I would consider this moot except as a matter of intellectual curiosity / scientific investigation.

Once a specimen shows evidence of internal corrosion, the options are:
(1) Salvage it as best one can by removal of the powder / neutralization of the primer compound.
(2) Dispose of it in its entirety (safely).
(3) Salvage the projectile for reloading, add the powder to the lawn fertilizer (the nitrates are wonderful for enriching soil) and dispose the casing.

I’ve loaded thousands, and more likely tens of thousands, of .30-06 with bullets salvaged from common ball and AP rounds which either had signs of corrosion or were loaded with “corrosive” primers. Often the corroded ammo will be a freebie and loose corrosive loadings frequently are cheaper than buying new projectiles of the correct weight / configuration for use in military firearms. I like to shoot cheaply!



Vlad–I have never tried to fire a cartridge with “Green Slime”, But I would guess they probably would not fire as the slime probably kills the primer. However, I’m not sure of this.