Felix the Cat
40 Cal
I have recently acquired a nice Wesley Richards percussion side by side in 16bore, and having checked out the barrels, took it for a test firing.. no problems, except that the left hand lock kept falling into half cock..
Having stripped down the locks I found that someone had been "playing" with the left hand sear and tumbler, which was pretty ragged. Having cleaned up the face of the sear, I examined the geometry of the tumbler. It would appear that someone had been reducing the depth of the bent by removing metal from the top surface, presumably to lighten the pull.. this had now lowered the release point for the sear, so that it was in line with the bottom of half cock notch rather than the top, so that instead of the tumbler correctly rotating, it fell into the half cock notch..
The solution was to add metal to the top surface of the tumbler bent to raise the release point. This was done using a TIG welder followed by re profiling with needle files and then case hardening and polishing with Water of Ayr stones..
I suspect that a previous owner was trying to reduce the travel of the sear in the bent, however chose to remove metal from the top surface instead of adding it to the bottom surface. There are a number of ways to achieve this. The modern solution would be to add metal with TIG or laser weld to the lower surface of the bent, however not everyone has this facility available to them. An older, but just as effective solution is to drill one or two small holes below the bent and glue or solder pins in the holes to raise the sear in the notch.
As in all trigger/sear work, be very careful not to reduce the trigger pull to dangerous levels.. the angle of the surface of the sear/bent should run through the centre of the tumbler axis as a starting point.
Having stripped down the locks I found that someone had been "playing" with the left hand sear and tumbler, which was pretty ragged. Having cleaned up the face of the sear, I examined the geometry of the tumbler. It would appear that someone had been reducing the depth of the bent by removing metal from the top surface, presumably to lighten the pull.. this had now lowered the release point for the sear, so that it was in line with the bottom of half cock notch rather than the top, so that instead of the tumbler correctly rotating, it fell into the half cock notch..
The solution was to add metal to the top surface of the tumbler bent to raise the release point. This was done using a TIG welder followed by re profiling with needle files and then case hardening and polishing with Water of Ayr stones..
I suspect that a previous owner was trying to reduce the travel of the sear in the bent, however chose to remove metal from the top surface instead of adding it to the bottom surface. There are a number of ways to achieve this. The modern solution would be to add metal with TIG or laser weld to the lower surface of the bent, however not everyone has this facility available to them. An older, but just as effective solution is to drill one or two small holes below the bent and glue or solder pins in the holes to raise the sear in the notch.
As in all trigger/sear work, be very careful not to reduce the trigger pull to dangerous levels.. the angle of the surface of the sear/bent should run through the centre of the tumbler axis as a starting point.
