The body, or tube, portion of the measure was formed around bar stock purchased at the corner hardware store. Different sizes for different bores. The idea being that the finished charger should be a loose fit into the bore while the ridge around the cap keeps the measure from flaaing down into the bore. The exact sizes escape me at this time but I had one size to form .45 caliber measures, one for .50 caliber and a third for .54 caliber bores.
Using my Treso adjustable measure I estimated the length of the body necessary to throw 90 grains of powder in the .50 caliber size. After assembly I would trim them down to the volume the shooter wanted.
With the .45 caliber chargers I would make them to a length throwing 70 grains. Then later cut them to the charge volume the shooter wanted.
Since I was making them in numbers I would cut a strip of tin plate with a width equal to the desired length of the finished measure. Then line up the edge of the tin with the bar stock mandrel and clamp that in a vise. Then gently bend the tin part way around the mandrel. Once the tube was almost completely formed I would use tin snips to cut it away from the strip and then finish bending to a closed tube.
Since I was making them in quantity I would clamp a heavy piece of music wire in the vise horizontally. I would cut a piece of wire sloder, slide it into the tube at the seam and slide a bunch of them onto the music wire. Take the propane torch and go down the seams of the tubes lined up on the music wire. With the seams pointed down the solder flowed into the seam easily. Left them cool and slid them off the wire. Usually having about 6 or 7 on the wire.
Next step was the caps on each one. I would cut strips of tin just a bit wider than the tubes. Flux the strip and suspend it in vice jaws slightly open. Stand the tubes up in a line on the tin strip. Drops chunks of solder down into the tubes and hit the strip from underneath with the propane torch. As the solder in the tube melted it formed a bead between the tubes and the strip. Left the unit cool. Then used tin snips to cut around the solder bead on each cap.
Most of the original tin chargers I looked at had little tin plate loops to attach a lanyard to. Holding the tin charger to a pouch strap. But shortly after I began to make these exactly like the originals there was a problem with the rough edges of the tin strap loops cutting through heavy string or leather lanyards. So I switched to forming loops out of wire instead.
I quickly learned that soldering the lanyard loops to the caps was a problem. If you heat the cap and loop to solder then the bead holding the cap to the body melts and the whole thing just falls apart.
So When it came time to solder the loops on the caps I would place the measure back on the metal forming rod and clamp that gently in a vise where the cap was soldered to the body. Then I could heat and melt the solder to hold the wire loop on the top of the cap without melting the bead of solder holding the cap to the body.
When I was doing this I was using acid flux and good lead/tin solder. I have no idea how well this would go with the present lead free solder. I know that this lead free solder is creating all sorts of problems in the electronic field.
Bill K.