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Powders & Humidity
- Thread starter jski
- Start date
NoSecondBest
New member
Heat and humidity are the two worst enemies of smokeless powder. Try to keep them in a cool dry environment and they'll remain good for many years. If kept in humid/warm places, the life is greatly reduced....greatly reduced.
You can usually do something about temperature, h
In reality once its stable at higher humidity unless you get condensation you are ok. There will be changes in burn rate if you open a container and load it fast vs some period of acclimation.
Temperature degradation would be a worse issue. Humidity might be after a long time but I am guessing over 5 years.
Keep it out of direct sunlight and store in as cool a place in your house you have and you should be fine.
We go upwards of 75% humidity in the summer, I have powder 30+ years old and its fine.
In reality once its stable at higher humidity unless you get condensation you are ok. There will be changes in burn rate if you open a container and load it fast vs some period of acclimation.
Temperature degradation would be a worse issue. Humidity might be after a long time but I am guessing over 5 years.
Keep it out of direct sunlight and store in as cool a place in your house you have and you should be fine.
We go upwards of 75% humidity in the summer, I have powder 30+ years old and its fine.
In theory....
Humidity and heat can effect the performance of powder. But, in practice, provided the powder is in its original container, I have had cans for more than 25 years. IMR4198 - It's been in storage [non-climate controlled], stored in my basement [high humidity levels in summer], traveled to TX, FL and now the NE. Works fine.
If you throw your powder, you will see weight discrepancies from season to season, but heavier loads [with the same volume] are so due to moisture, which lowers the performance somewhat. This is why it is important to understand the area from which a person lives/shoots if you are taking loading information from them.
It would be extremely difficult to ruin powder if in the original container. But, humidity levels during reloading might make long term consistency more difficult.
Humidity and heat can effect the performance of powder. But, in practice, provided the powder is in its original container, I have had cans for more than 25 years. IMR4198 - It's been in storage [non-climate controlled], stored in my basement [high humidity levels in summer], traveled to TX, FL and now the NE. Works fine.
If you throw your powder, you will see weight discrepancies from season to season, but heavier loads [with the same volume] are so due to moisture, which lowers the performance somewhat. This is why it is important to understand the area from which a person lives/shoots if you are taking loading information from them.
It would be extremely difficult to ruin powder if in the original container. But, humidity levels during reloading might make long term consistency more difficult.
If you pick up a copy of Norma's current manual, it shows they store powder for shipping in around 50% RH (40-60%, IIRC). Even in a loaded cartridge, it gradually equilibrates to the RH of the environment over a period of about a year. Going from being stored in 80-85% RH to being stored in 0% RH causes the burn rate to increase about 12%.
All that taken together means that if you store the powder with desiccants, you can expect faster burn rate performance. A load developed in an arid desert environment will wimp down a little over time in a wetter environment. A warm load developed in a damp environment then stored in the desert or in a box with desiccants for a year may start giving you sticky bolt lift and other pressure signs, not to mention the velocity probably having moved the barrel time of a sweet spot.
All that taken together means that if you store the powder with desiccants, you can expect faster burn rate performance. A load developed in an arid desert environment will wimp down a little over time in a wetter environment. A warm load developed in a damp environment then stored in the desert or in a box with desiccants for a year may start giving you sticky bolt lift and other pressure signs, not to mention the velocity probably having moved the barrel time of a sweet spot.
jski wrote:
How vulnerable are smokeless powders to humidity?
Humidity is a potential problem if the powder is exposed to it. If it is inside a sealed container where humidity cannot get to it, it is not much of a problem.
Should they stored in a climate controlled environment?
It won't hurt. It might help.
On the other hand, I am still loading and shooting powders that I purchased in the early 1980s and have had stored in a lakeside garage in Arkansas then later moved to a garage in North Texas that still perform the same as they did when I loaded cartridges from the same container 30+ years ago.
FrankenMauser
New member
We had a pretty good discussion about component storage a few years ago, but I can't dig it up right now. Must not be using the right terms...
Anyway, the simplest way to look at it is:
Stable temperature and humidity is what you want.
Assuming storage in factory packaging:
Humidity swings degrade primers.
Temperature swings degrade powder.
Anyway, the simplest way to look at it is:
Stable temperature and humidity is what you want.
Assuming storage in factory packaging:
Humidity swings degrade primers.
Temperature swings degrade powder.
FrankenMauser - "Humidity swings degrade primers"
That's for sure. I've tried using "older" primers a few times with an increased failure to fire as a result. Probably due to their packaging, which is about as air-tight as a sieve. I now keep them in Tupperware containers [in their original boxes]. So far, so good.
That's for sure. I've tried using "older" primers a few times with an increased failure to fire as a result. Probably due to their packaging, which is about as air-tight as a sieve. I now keep them in Tupperware containers [in their original boxes]. So far, so good.
Interesting on Humidity on Primers.
I have shot primers that were 20 to 30 some years old.
One group was in a wet environments.
I know one sharp shooter that got a load of wet primers and dried them out and shoots them.
At least from my experience humidity does not seem to be an issue.
I have shot primers that were 20 to 30 some years old.
One group was in a wet environments.
I know one sharp shooter that got a load of wet primers and dried them out and shoots them.
At least from my experience humidity does not seem to be an issue.