I don’t have one caliber that ever gets filled up with smokeless like black powder. What do you do? Nothing. 
I either put some cotton in and tamp down or use a wad which works for straight wall cases but not bottle necks. Some shooters I know just do nothing. Add powder, apply bullet.

Long ago, I found a Victorian overstuffed chair at the dump.  It was unrestorable, but I ripped open the cushions with my trusty Scout knife (yeah; that long ago) and filled a shopping bag with the Kapok filling.

I don't use it often; only with cast bullet smokeless loads in cavernous or long cases.  A little pinch of the stuff, tamped down with a pencil eraser, expands to fill the cross section area of most brass shells and keeps the powder against the primer with normal handling.

The Kapok is some kind of fine fluffy orange colored plant fiber, like dandelion parasols, and is instantly consumed when the powder burns, so there's no obstruction potential.