Decades ago I found an old seat cushion at the dump, ripped it open and took about a half-shopping bag full of Kapok home.  I still use that on the rare occasions I need to keep a relatively small smokeless charge next to the primer in a large case.

It’s orange, fibrous stuff that disappears in a flame.  No melting; just gone.  A tiny amount, teased out, is enough to grip the sides of the shell and hold the powder down.  I push it down against the powder with the eraser end of a pencil.  It can be shaken loose, of course, but normal handling is OK.

I notice the difference in accuracy in freakishly long cases like the .40-3-1/4” Sharps Straight, with bulkier powders that burn incompletely when the pressure drops, like 4759 and 5744.  Otherwise, it’s an extra loading step that I’d rather avoid.

No chamber rings yet.

I shoot blackpowder cartridge, Always with wad over powder
have a 38-55 using a thin walter card wad and a 45-90 using a .060 low density polyethylene wad over the powder. shoot bought accurate

Barrabruce
In Charlie's expariments he Proved that the worst stuff that you can use is Dacron. it turns into a sticky goopy plug that asserbates ringing.

40 Rod

Thanks 40 rod.
I think I’m seeing my little Dacron wads down in the grass unburnt.
But then I also get some black mummies and bits in cases also at times.

I will see if I can find some kapok.
I have tried cotton balls teased out but didn’t like the way it compressed into a hard disk easily.
And anything that may smoulder is a big no thanks to me as setting the country ablaze is not what I would be liked to remembered by..

The smoke on extracting the case is grey white maybe a touch of green.
Could it nitroglycerin in the powder?
I have some SK std plus tin of 22lr that I find is also plastic like smell to it also.

Thnx I’m enjoying this thread.

I could just maybe put a thing paper wad on case mouth and try that to see if it would work also.