Almost all of the time for me and a wide varietyof bores,a wad under a PRB or a conical will not only give greater accuracy, but also allow for a heavier powder charge as the wad protects against gas-cutting.
Here is a great link to make your own wads. You need a punch, felt and lube. I use the durofelt.
www.durofelt.com.
Also for lubing your newly cut wads, put them in a shallow bowl and then pour melted bore butter over them then remove after cooling.
Here is a great link for information:
http://history-sites.com/mb/cw/cwaemb/index.cgi?noframes;read=1135
Tahquamenon