Well, lets address the filler issue first. Basically, you use a filler when you have a very light load of powder that won't remain against the flash hole in various positions of the rifle. First and foremost, do NOT put the filler in tightly! This can cause chamber ringing and up to chamber explosion! It will also produce varied results in POI. Most cases will be filled plenty with a good charge for hunting purposes and not need a filler. If you are using jacketed bullets then caution should be used because they create more pressures than non jacketed. As far as crimping goes and seating depth, I usually use a moderate crimp and I try to seat my bullets to a depth that is the best distance from the lands. Compression of the load is something you would rather avoid if using a filler. If compressed, the filler can act similar to an obstruction and cause heavy pressure spikes. BUT you want slight to medium compression if NOT using a filler. I know, headache time

I weigh my loads just like smokeless. Volume measuring is just too inconsistent. I use a drop tube and trickle method for consistent powder settling. I never light load so I don't use fillers. If you are light loading then use of a veggie fiber wad is touted to be about the best. Consistency in BP loading is your absolute best friend. My OCD is a plus when BP cartridge loading. Helps to be a little crazy sometimes Hope I haven't confused you too much Clem. Any other questions feel free to ask.