A 3/8" dowel works well for .36 and a 7/16" dowel works for the .44. That's what I've been using, no problems, Just wrap the paper SLIGHTLY loose on the 7/16" dowel for the .44's.
I wrap the paper around the ball and glue it to the fat part of the ball on .44's and my dowel is concave on the end so the ball will sit in it while I wrap the paper around the dowel. Once it's glued it'll slip of the dowel and you add your pre-measured powder charge. Twist the end and tie it off with thread or you can fold it and tie it off or just glue it and cut off the excess. You want the dowel a little smaller than the ball so your powder doesn't bunch up and make the cartridge bigger than the ball.
