Some powders are more temperature sensitive than others. None work well when not in proper amounts. I load on couple of Spolars so have established a habit of weighing the first four loads, then one about every 25 until I have about a hundred loaded. After, that if all has been right on the money, I just load as long as my mind does not drift away. Loading hundreds of shells, in a sitting is efficient, but you always need to be paying full attention as you go. One mistake repeated will make you question why you ever load in the first place.
My best output, for a single loading session, was 4000 .410 shells with just two screw ups. Both were minor wad/crimp issues. Never had any issues with that lot and need to do another session like that soon. 4,000 shells goes faster than you would think when all you have to do is grab boxed shells off the shelf. I love getting 800 loads out of a bag of shot. Shot seems to last forever when loading a .410 compared to loading 12's that seem to have shot run out like a stuck pig.
