Is reloading in a sauna safe??

[CJW]

[Harpoon1]

High humidity is a powder killer!

https://youtu.be/h3lEAWqyREk

https://youtu.be/pzDHRwi3QVk

[jasper2408]

Another good article on this subject.

https://chronoplotter.com/2021/08/19/how-does-humidity-affect-powder/

[Klem]

Chuck,

I think you are fine, or this would be a reported concern already.

I agree with harpoon, unless you pre-cook your ammunition on the dashboard of your car in direct sunlight then humidity ought be more of a concern than temperature - and only for long term affects on powder storage. Obviously loads that give certain velocities/pressures in winter will give slightly higher pressures in summer, but unless you are loading on the raggedy edge all I do is expect a 20-30fps increase in the same load between summer and winter. Our bench-resters load at the bench all year round and they are a careful lot. Our summers get as hot as yours, but not as humid. I see Atlanta gets up to 84% humidity this time of year but not sure what it is further north.

The amount of moisture in powder degrades it more than heat. Long-term, moisture eats up the stabilizers which then leaves the powder to form acids and self-disintegrate. Otherwise your powder properly stored with the lid on should last decades (single-based lasts longer than double-based). When moisture gets in it doesn't get more dangerous, it just gets less energetic. In Australia the entire handgun batch of the new ADI processing plant was thrown out recently because of high ambient humidity. Apparently they were trying to extract as much moisture as possible before selling it but it did not pass quality control. There is currently almost no handgun powder available in Oz, and the handgunners are hurting.

I have heard of shooters putting small desiccant packets in their powder containers to absorb moisture when in storage but probably overkill.

[CJW]

[LRRPF52]

I have loaded on the range with a friend who was big into Bench Rest, with his range press, in near 100 degree heat.

No need to re-size the brass since his chamber was so tight. 6mm PPC (10rd into 1 bullet hole) rifle at 100yds.