The barrels are from a Spanish breech loader that was given to me as a basket case; the hammerless lockwork had given up the ghost and as it was, in my humble opinion, very ill designed without much regard to the laws of mechanics, I decided to put the excellent chrome bore barrels to good use.
Firstly I made two chamber inserts that are bored to form chambers leaving one inch of solid metal at the back.
I intended to make both of them from Nickel Aluminium bronze (which is tougher than mild steel) however after machining one I made the other out of mild steel, which was far easier to cut.

The cuts were gentle only a couple of thou at a time and were done on the side teeth and advancing from the outside to minimize any tendency to climb.
Finished up within a few thou of being square to the bores.
I'm using the tactic that having posted my initial progress I'll keep going.
