I have used a lot of L & R locks over the years. During the last quarter of the 20th C, their percussion lock was all we used on the Fraser River Hawken that Don Robinson's (RIP) shop produced, and they required very little if any tinkering to make them suitable.
More recently, I have had issues that required some careful thought and re-working to make them suitable, and I have sent the company my observations together with an extensive collection of photographs to illustrate my concerns. They didn't even reply to my messages, let alone remedy the deficiencies.
In this instance, we are looking at the Ashmore (Hawken) flintlock. In this first image, you can see that the assembler has ground the sear spring way too short, causing the working end of the spring to bear on the sear way back along the sear. This creates an extremely heavy trigger pull to the point that it is very difficult to trip the lock when out of the rifle. Coupled with that, the sear's boss where the screw passes has a rounded back shoulder, further inhibiting the action of the spring. This is evident in the second image where the contact point is clearly visible. So there are two jobs here, ie: lengthen the sear spring and provide a proper contact point for the spring's working end to contact the sear. The next image shows the sear having been filed to take care of the second issue.
Also in this picture you can see that I have lengthened the spring and tapered the working arm.
To stretch the spring, I first heated the spring red and unfolded the metal flat, gently tapping while red with a hammer to remove irregularities. While I had it flat, I tapered the working part both in thickness and in width. This is simple file and polish work, requiring only a few minutes. Then the spring was re-heated red and a new bend applied so that the working arm was longer by nearly 1/4". this solved two issues, ie: the tip of the spring was now in the correct spot on the sear, and the bend was further inside the lock plate, making inletting easier. I have photographed a before and after spring together to illustrate the change.
The final picture shows the spring installed. The action now is crisp, light, and solid. The company wasn't interested in rectifying the issues, to my great disappointment. I will address a third issue when I return....
The next issue and it's a problem for lots of locks other than L & R's too. And that is the sear screw bottoms against the bridle before the threads stop the screw from going in too far. This jams the bridle against the tumbler. The easy fix is to back the sear screw out a turn or so but this goes against my idea of how a lock should work. So to allow the screw to go in far enough to bottom on the THREADS and not the bridle, I just put the screw into the chuck of my drill press and with a 6" bill bastard file with the edge ground safe, I shorten the height of the head from the inside, resting the safe edge of the file against the shaft of the screw. It is necessary to take off some metal, but a trail and error fit and repeat in the press gets the job done. Now the screw bottoms against the threads and the lock plate and the tumbler is still allowed to rotate as it should. These screws are heat treated, so one needs a good new file for this job.
This pictures shows the screw having been altered as I described.
