Guys,
I am finally assembling the gun I have been working on for a while and showing the steps on this site. One problem, I remade an old wrought iron percussion barrel that started as a straight octagon, .36 and made it into an octagon to round .42. The barrel is about 0.9 across the flats at the breech and is straight sided. I want to make a Lehigh gun where the wrist is wider than high, but with a straight sided and thin barrel, how do you do it?
When making the lock I left the lock interior bolster block a good bit higher than is usual. I made it about 0.35 above the lock plate interior rather than the usual 0.25. In order to get the proper dimension at the wrist I tapered the bolster block so that the lock plate acts like it is mounted to a tapered barrel with a nice thick breech. Looking at this photo, I hope you can see that the tail end of the lock plate is flared much more away from the barrel than the nose end. This is how the wrist area would look if using a swamped barrel with a good 1-1/16 breech.
This photo shows the lock plate with the tapered bolster block and the angle it would make with the barrel surface.
This photo shows the two lock screws and the difference in length due to the taper of both the lock plate and the side plate surfaces. This is what you expect when using a nice swamped barrel, or with this "fix".
Another way to do this is to buy a store-bought lock and solder a thin plate on the bolster block, then file the plate to a taper.
Now it is easy to get that wrist wider than high and have a nice Lehigh gun.
Jim