Thanks for the kind comments. Yes.....cartridge brass works great. Just looks a little on the modern side...
These are made from commercial brass thin wall tubing of a size appropriate for the bore diameter, but on occasion I hand make the tubing out of silver or copper and, in one case, 18 karat gold.
Hand made copper tubing.......I took a picture of a tube with a soft soldered seem that is not complete so you can see how the tube is made up. You must cut the sheet material to a precise width. Too wide and it will wrinkle going through the die. Too narrow and it will leave a gaped seam that will be difficult to solder. If the tubing is hard soldered, as I do with silver and gold, you can make the tubing oversized to begin with and then draw it down to different sizes just like you would draw wire. Depending on how thick the sheet is and what diameter tube you are making, you may have to fill the precursor tube with lead or, better , cerrosafe / cerrobend to keep the finished tube from wrinkling as you draw it down.