and therefor I like to make my own from the cheapest material I can find.
That is a 100% wool felt hat that you can find at thrift shops for about three bucks. You want it to be a man's hat since the felt in a man's hat is much more dense than a woman's hat. Check it out. You'll see what I mean. One hat will make about a billion wads.
You can also get "Durofelt" which is very good. Thicker than hat material and consequently makes a more substantial wad. I don't know a good source for Durofelt but I am sure someone will wade in with a link or something. (Mykeal, Gary, What do you think?)
As regards fit I think that slightly oversized is better than slightly undersized.
I bought a set of punches from Horrible Freight: http://www.harborfreight.com/9-piece...-set-3838.html
The 7/16 is a little small for .44 and .45 and the 1/2 is a little large. I think the 1/2 inch is the choice.
The 3/8 is perfect for .36 cal and for .38 and 357 BPCR
5/16 is good but not perfect for .31.
You can go to Dixie Gun Works and buy special punches at about ten bucks a piece but the tightwad in me recoils in horror at the thought.
In addition, the wad punches that you get specifically for that purpose do not chuck into a drill press. They are made for use with a hammer. These punches from Harbor Freight work either way.
As regards thickness, the durofelt that folks like to use is (IIRC) 1/8 inch. This is thicker than hat felt and what it means is that you have to use two hat felt wads to get good lubrication.