How do you tell if powder is going bad?

[M8ball]

Got a can of H4198 that I've had for about 6 years. Should be good but I noticed when I opened it up (last used a few years ago) it had a fairly strong smell to it, kinda like rubbing alcohol. I haven't had powder around so long that I know for sure has gone bad, so I thought I'd ask the veterans in the house what genuinely bad (as in do not use) powder smells like. I've heard "noxious", but what exactly does that smell like? Strong chemical smell or a college dorm restroom after a Taco  Bell and Coors O bender?

[Savage]

Assuming it has been stored in a reasonably stable temp and humidity environment, your powder should be fine. The odor you describe sounds normal for powder that has been stored for a few years. A friend and I just loaded some IMR4895 that I have had for 30+ years. Couldn't tell any difference from the new stuff. If you are a benchrest shooter it might make a difference, but for general use, it should be fine.
Savage

[myronman3]

if i have any doubt about quality or what kind it is,  it gets trashed.   when in doubt, throw it out.

[GREYGHOSTt]

Any kind of a solvent smell is good er  alchol acetone ether.
Ammonia is bad and also on visual exam the powder usually has a rust color dust on it.

[kevthebassman]

when in doubt, throw it out.

Wise words.  If it doesn't look right, sprinkle it on the garden.

[huntswithdogs]

I've got a couple of cans of 3031 and some Win 748 that have been around for quite some time. I've been using them with no problems.

I read in one of the reloading manuals, a long time ago, if powder smelled like spoiled milk to toss it. I don't remember which boof it was. I started reloading a long time ago and my memory slips occasionally.

HWD

[iiranger]

Gunpowder is the nitrated form of cellulose, the basic carbon hydrogen unit of life. It is nitrated in strong sulphuric and nitric acids and then washed MUCH to get the acidic residue out.  One source of the cellulose is cotton, just like your underwear, well, mine anyway. Thus one old name "gun cotton."  "Double base" powders have some nitroglycerin blended in. Glycerin is an oily fat (at room temps) that is nitrated in strong sulphuric and nitric acids THEN WASHED MUCH...

The organic chemical paste is worked with organic solvents. Alcohol (as in booze but there are hundreds. Cholesterol is an alcohol.) Acetone as in nail polish remover.  Ether as in starting fluid (which is usually alot more hexane. Ether too explosive.). If you smell these it is normal and o.k.

There was one batch of single base made by Dupont IMR for the WW II get together according to the NRA. Government ordered that the final washings be skipped to get it into use more quickly. Saved a couple weeks. Soliders need ammo. BUT the war ended and some of this batch got into surplus circulation. Lots of acids left in the powder. It "rotted" cans and sacks and anything else it was put in. This is where the story got started. This smell would remind you most of vinegar. BAD. BAD. BAD.

Gun powder is a form of "petro plastic" as we know them today. If it is stored in conditions you could live in, it is probably fine. Leave it out in the weather... like most organic materials, something will re cycle it. If you smell the vinegar or ammonia smells, then it may be going bad. Otherwise, stored right, it should last half of forever. If you do get the vinegar or ammonia smells of "break down" then sprinkle it on plants. Lots of nitrogen and should fertilize them fine for lots of nitrogen fertilizer. Happy new year. luck.

[Siskiyou]

The bad batch of WWII powder was a lot of 4895.  It turned a rust color.