Funny you should mention the discoloration of the bottles and "ruination". I noticed a crack in the powder bottle tonight as we were loading (remember we bought this as "used", even though it was still in new condition...it obviously sat for a long time in someone's basement or something). I started to remove the bottle and it totally fell apart in my hands! Fortunately, I didn't cut myself on the sharp plastic, and I didn't end up with powder everywhere. I was able to tip the powder into a bowl and save it, and then put on gloves to remove the rest of the bottle. We'll be picking up TWO new bottles when we go to the store next, the shot bottle is the same yellowed, brittle-looking plastic. So the powder is stored in its original container now. If we know it's going to be a two-nighter reloading fest, we'll leave the powder in the bottle overnight and empty it when we're done on the second day.
AND...and update to the problem of consistent throws that are the proper weight. WE DID IT! I figured out what we needed to do! Before each throw of powder, I tap the top of the bottle 5 times with the 3 middle fingers of my hand, about the intensity of "table drumming". This packs the powder in just enough. We were getting consistent throws right around the 12.3 mark with the recommended #18 bushing. Some were a hair light or a hair heavy, but they were all where we felt totally comfortable. I wrote down what we did so we don't end up forgetting (usually for me, if I write it down, I will remember it without having to refer to my notes). I hope that helps another newbie to shotshell reloading. I think this Win AA Lite powder is just that....LITE and needs a bit of encouragement to fill the bushing properly. We ended our reloading session weighing only every other shell. Next time we load, we'll weigh the first few, and then probably only every 5 or so until we gain more confidence in the process.
Thank you ever so much y'all for taking the time to share your knowledge and thoughts with us. We're on our way to reloading a lot of shells now that the frustrating part is over!
Lil and Outrider