Shelf Life of Powder?

[BetaShooter]

What's the shelf life of powder? I came across some powder I had stashed in my garage that's about 10 years old. It's unopened and the factory seal is still in place. I'm one of those overly cautious guys and I don't want to blow myself up; therefore, I'm leary about using it. Can powder go "bad"?

 

[boilingleadbath]

Smokeless powder is mostly nitrocellulose, and nitrocellulose CAN decompose, and this decomposition is autocatalytic. Now, while I know that "decomposed" nitrocellulose is more sensitive, I don't know how that affects it's burn rate - though I'd bet that it makes it burn faster.

In more normal words - 'powder probably can go bad, and it'll tend to change it's preformance quickly.

Of course, 'powder isn't pure nitrocellulose, so I'm not sure the above information is relevent.
I mean, those surplus rounds from the 1950s are still fine, arn't they?

 

[Lone_Gunman]

10 years is not a problem.

There is a good bit of Yugo 8mm Mauser ammo on the market right now that is left over from the 50's.

 

[NailGun]

BetaShooter, here is a link to Hodgdon. It discribes the signs of powder decomposition. Hope this helps. http://www.hodgdon.com/data/general/deterioration.php