This is for holy back powder only, not substitutes
This is where the fun begins. For all you reloaders, throw out most of what you know about smokeless powders.
BP is measured by volume not weight. So your scales are worthless. You have to get a volume tube.
Lets load a 45/70/405 carbine round: 45 cal 70 grs BP, 405gr pill.
Measure your load:
First take your powder and measure out 70gr by volume.
Next place your case under the drop tube. Pour the powder down the tube into the case.
WHY? you ask. Because it sends the oblong grains straight down like spears (No Robert NOT Britney)and they pile up in the case, giving you the LEAST amount of free space in the case.
Remove the case, INSTALL a veggie wad, to contain the powder or you compression device may steal your powder.
Use a compress die (or round stick the same size as the case mouth. For 357 or 38 I use a pencil. 45 cal I use the die.
Veggie and milk carton wads:
You can make or buy .030 and .060 veggies wads, or do like we did and buy bulk wad rolls and a wad cutter. Ive made 1000s per sheet of wadding.
Milk carton wading. Some in the casting world believe that you need a wax barrier between the wad and the boolit. We have never used these. You can cut them out using the same cutter as above.
How much do you compress?
What I do, isnt what a lot of folks do. I take a boolit and case with NO powder or primer in it. then I seat the boolit to the proper OAL. Then I stick a coat hanger up the primer pocket hole until it hits the boolit. Measure the coat hanger.
This is where the veggie wad and powder will stop to ensure a solid compressed fit.
While compressing make sure the distance form your wad to the case opening is .001-.003 higher than the mouth of the case. Smush the boolit to the OAL, and you have a solid BP round.
If you ever have an air gap, you will know by the over pressure report. It is startling.