Bert, in responding to your DW .44 mag. thread you already know I believe that #7 or Ramshot True Blue will work better for you. #5 is an excellent powder for a lot of different types of loads and I have used it also. Accurate believes it is the ball powder equivelant of Unique in it's flexibility and I really couldn't argue that. #7 is denser and will meter even better. Density as rated in grams per liter is something worth knowing. #7 is 985 grams per liter and as far as I am aware, it is the densest pistol powder available today so when someone says, as I do even incorrectly that it meters like sand, that's not quite right. It's better than that. Grain size is extremely small, but I covered all this in your .44 thread.
As far as your rifle cases, what brand dies are you using? Some think I am snobbish with my constant recommendation of REDDING dies, but I guarantee you, it's not because I like to spend more money so that I can feel superior because of my high dollar dies. (I would go buy a Corvette insted) Redding machines to the tightest tolerances in the industry with the hardest steels available and geometric tolerances are something I happen to understand fairly well. I don't buy handtools at Wal-Mart for the same reasons. I full length resize rifle cases and that is enough for a heated debate right there. If others feel neck sizing gets it done, hey, I'm all for it. I do a number of things in reloading that may not seem necessary and after 20 years I still use a single stage press so I can do other things I feel necessary to match grade ammo during the process that make a progressive little more than a concept of high production. I clean primer pockets almost every loading and I know most don't and don't believe it's necessary. It's their ammo and I know how mine works. REDDING full length resizing dies for example will give you a very concise explanation of setting your dies to match the chamber of an individual rifle and neck sizing is the reason a lot of reloaders go that route because returning the neck to factory dimension gets them back to shooting for a particular rifle. Your brand of dies may have nothing to do with the ring, but I don't get them with REDDINGS.
Your tumbling and still slightly dirty case necks are not hard to understand if you think about it. The media is being displaced by the larger diameter of the case body and so less pressure is exerted to the case neck and like many have pointed out there are many good solutions. Soaking your brass in water diluted apple cider vinegar before tumbling is another. Make sure the cases are completely dry before they go into the thumbler.
Case trimming is another area of great dispute here and there are all sorts of remedies. Mine is the Lyman Case trimmer. I trim pistol brass usually once to get all of my cases to one uniform length and this is mainly for consistency when taper or roll crimping. Magnum revolver rounds are a little more likely to stretch than autopistol brass and some find it uneccessary to trim at all and discard the brass if it does get overlength. Rifle cases are a different story and should be checked after each loading. I treat Magnum revolver loads in a similar fashion in case they end up on a hunting trip and I want either to be the most accurate thay can possibly be.
After 5 years of reloading, you sound like you have a pretty good handle on things. The one thing I feel some take too lightly is the burn rate geometery of the powders they use and if one really wants to use the best powder for a specific load, it is worth the time to read and understand pressure curve charts and all of the engineering specs associated with a given powder. There are many powders that will do a number of things well, but only a few will be the best and when you can do more than just analyze a burn rate chart, you can start doing things like accurately predicting which powder might be best for your .357, .41, or .44 Magnum rather than discount the fact that your guns may vary in barrel length from 2.5-10". You buy guns to accomplish different task and you buy gunpowder, bullets and primers for the same reason.
