I have reloaded for a .53 pinfire pistol and also for 16 g pinfire shotgun. First important point is to use brass or copper pins. I used silicon bronze ring nails used in boad building, and filed the rings off. Steel pins (finishing nails) will dent the hammer faces and possibly damage the tumblers.
What was important for me was to use a relatively thick base and have a recess (5/16" D I think) in that base. I found that when the #11 cap was too far away from the center of the shell, I did not get reliable ignition. When the cap sat (upside down) in the recess, ignition was reliable.
I put a heavy paper disc between the priming compound and the end of the pin, for safety, if the shell was dropped or the pin turned.
I put the cap in the shell, put the pin into the cap and then put a drop of airplane glue on the outside of the shell to keep the pin in place. It dries away to nothing and does not interfere with chambering. If the pin comes out a touch and you push it back it, usually no ignition.
The bullets I used were healed and I made my own mold from a second hand Lee mold.
Would strongly suggest making your cases out of solid stock for the heads and either solder tubing on for the body or make the whole shell from solid stock. If making the whole thing from solid stock, only the last .1" or so needs to be thin and the rest of the wall can be relatively thick. Can save a lot of time and fuss in boring out the case.
Almost forgot; I used an end mill to drill the recess for the cap and it was a little deeper than the cap is wide.
cheers mooncoon
