would it be better just to leave powder outside in my unheated garage. or keep it in the house and just take it out when i shoot? does the temp humidity change from going in and out hurt the powder???

Inside for me. Better humidity control during storage seems the be the more important factor.

This is what I do!
Just take enough pre-loads outdoors - not the entire jug. Then keepwhatever preloads not used in a separate container upon returning to the home. Use from the original dry jug the nexttime out- then return the unused preloads again to the separate container again/the next day.... etc...etc. When done with the original jug, revert back to the 2nd container.

Most times afterwards, that 2nd container remnants will shoot identical to the original jug. But what you just done was played it safe -- not allowing "possible' moisture contaminated powder to be re-mixed with the fresh dry powder.

So what you're saying is.......the second container, containing "possible moisture contaminated powder" will shoot identical to the new "fresh" jug?

That's the most ridiculous thing I've read from you yet, Joe.

Everybody has their own way,I keep mine in the house in the gun safe [its very humid here on the down wind edge of Greers Fairy lake] the gun safe has a small dehumidifyer. Lee

ihuntbuck

Gees! just re-read your question -

The "question" my powder is stored at room temp on dark cabinet. It never changes temperature, from any extreme to another.

I would think that moving it from extreme to extreme might cause some decay in performance - but I have no way to prove that....

after the season i vacuum seal my powder and primers.

I dont keep powder around long enough to worry about it going bad.

I keep my Powder horn full of powder until i no longer have any. Although i have had a can of 4f for a little over 2 years now. It sits in my closet and i open it when i need the stuff.

thanks for all the replies. i just opened my second pound of t-7 and had a very consistant range session with my new nosler bullets and was just wondering if there was any tricks to keep powder fresh and if you guys thought accuracy might suffer from moisture getting in the powder from going in and out.....