What's going on here?

[Texas by God]

Yesterday I pulled down a handful of 45 Auto Rim ammunition and noticed two different looking powders. These of course were Remington( the only source of) factory loads with 230 gr hollowbase lead bullets. I disposed of the powder after taking a picture of it. I have no sense of smell so I couldn't tell if the brown powder had degraded.
Any clue?
Thanks

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[Bent Ramrod]

The powder at the top hasn’t been tumbled in graphite; the sample on the bottom has.

I have taken old rounds apart for components and sometimes find such powders. I found some REM-UMC smokeless loadings for the .45-70 (with suspected corrosive primers) that were evidently loaded with Sharpshooter powder (as pictured in Sharpe’s reloading book), and it was that greenish-yellow semi-translucent color.

If the powder has gone bad, it will have a sharp, sour odor, and clump together, and the surface of the granules might be actually sticky or gooey. Also, you may see blue-green corrosion on the interior of the shells sometimes.

[Texas by God]

Thank you.
The brass is all shiny clean inside.

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[kevin c]

I was under the impression that commercial ammunition, at least the pistol plinking varieties, is made with large lots of powder that the ammo company tests the burn characteristics of. A load is created with the desired performance parameters. When the powder is used up another lot, not necessarily identical to the previous one, is tested and a new load worked up that matches the performance of the first.

All that to say the powder may not be the same from one lot of ammo to the next, but the performance is hopefully similar.

[Der Gebirgsjager]

How old is that ammo? Can't be too new, I would think, as I haven't run across any newly minted .45 Auto Rim in a long time. I've shot loads with powder that looked like that, and it has a different smell-- which doesn't do you any good at all, I know. But the ammo seemed to perform as normal. Also, I've seen and shot foreign military ammo with brownish powder. It was probably 50-70 years old, but did shoot.

DG

[Bent Ramrod]

Kevin C is right. The powders bought by the ammunition companies might be formulated and processed and look exactly like the specially-blended “canister grades” we buy, but the burn rates and pressure characteristics will vary significantly, both from those of the canister grades and from lot-to-lot of the powders themselves.

The ammo companies have labs with combustion bombs to test these characteristics, and once characterized, that lot of powder can be loaded safely. The bigger surplus outfits that sell “data powder” recovered from broken-down ammunition have access to the same equipment, and do the same thing, but the recommendations for loading are necessarily narrower in scope than the data for the canister powders. Fewer calibers and cartridges to use it in are covered by the recommendations.

As my old Mentor used to say, “Thermodynamics can be calculated very precisely beforehand, but Kinetics is in the lap of the Gods.” Thermodynamics is total energy yield; Kinetics is how the energy is released, ie, burn and pressure characteristics. People have done a lot of work trying to model Kinetics, with no success whatsoever. The only way to get the data is by experiment.

You can, if you’re sufficiently experienced and careful, generate your own data from such powders by experiments with your own firearm. This method does have its hazards, of course, and generally the data doesn’t necessarily translate to other firearms, even of the same caliber and chambering.