If I were flying, I'd have my cartridges in a sealed container that can withstand the pressure difference. And, in the container I'd have the appropriate humidity control pack. Then I wouldn't take the cartridges out of the container until I was ready to use them. Leakage isn't instantaneous and neither is the transfer of moisture. So, the time from removing the cartridges from a climate controlled container to chambering and firing, shouldn't amount to much of a factor.You clearly have a log of reloading experience, and your comments are all valid, but my attitude is instead of giving up and living with all these issues, i am more interested in how to resolve them. So very open to fresh ideas.
Yes, loaded rounds exchange air with ambient once there is a pressure differential, either because a low pressure/high pressure system moved in, or you took your ammo on a plane to a match. Have seen this happen over a 3 month period by weighing loaded rounds on a milligram scale, posted some results elsewhere on this site. Effect is very real. Tried sealing the cases (using the Ranger industrial sealant), that stopped the weight changes on 90% of the loaded rounds, but the variable amount of “glue” in the neck changed the neck tension and did more harm than good to the SD of the batch. So a failed experiment. If you know of a better solution, i would be curious.
For hunting, some kind of sealant would be best; something like some manufactures use on some of their ammo. Wish I knew what that is.
Not trying to “worry”, not trying to scare anyone, just trying to identify what keeps my SDs at 7-9, and what to do to get it to 4-5 fps….
Btw: Bullet weld was the major issue for me, caused my SDs to start off at 12-14 fps, and mostly got that resolved: Tumble in walnut media with 2 teaspoons of mineral spirits plus a tiny amount of polymer car wax mixed in, for 2 hours only controlled via a timer (don’t over clean the inside of the necks), use Neolube nr 2 on the inside of the neck, seat long, reseat the morning of a shoot. That took my SD from 12 to 8. So on to the next problem.
Looking for ideas to get to 4, and what experiments to run, not trying to tell anybody what to do…. Humidity variance looked like a viable candidate.
Agree, about not cleaning the inside of the necks. After annealing and cleaning the outside of the necks with steel wool, I like to tumble with white rice (medium grain) after I've sized them having used Imperial Sizing Die Wax. The rice absorbs the wax lube and apparently leaves a very thin coating on the inside of the neck, which makes for nice and consistent seating and no bullet weld; at least, no detectable weld in a 6 month period that I've experienced. The outside of the cases are cleaned nicely, though not what one can get with wet tumbling, but that's not my goal anyway. Here's what my cases look like after 5 firings using this method: