Hi there, unless you have access to a lath or some who has it's not worth the bother. My repro shotguns are 12g. To make my wads I use a 20mm wad punch (from any good engineering shop),the material I use is carpet felt, which I then put in little metal tudes (less than 14gauge)they are then dipped in an old chip frier which has a 50/50 mix of bees wax and vegitable lard, I have used animal lard but that can go rancid. You may have to alter the preportions depending on the weather temp. For the heavy card I use a 19mm punch, I use 1/8th + card and a thin 180 GSM over shot card cut with the same 19mm punch. My clay target load goes like this:- using equal volume of FFF powder and shot (No 7 for flint and No9 for perc) 1 & 1/4oz of shot. The load goes like this, powder, thick card, waxed felt, thick card, shot, thin over shot card. The cards are not a tight fit as the waxed felt does the sealing, the thick cards only protect the felt. Please remember all shotguns will shoot slightly differently as well as the shooter behind the gun, so you will have to spend time on the patern board. Another note, both thick cards and felt are put down the barrel in one go. I hope this helps, happy shooting.