This thread is amazing to me because I very recently encountered many of the same issues with an L&R replacement T/C lock. It amazing because, now, in 2024 they still haven't addressed them. I am not an expert like Dave, by rights I have no business even attempting, but I've been a tinkerer all my life. I muddled my way through and got an acceptable (to me ) result that is much better than the original T/C lock, and a big improvement over the L&R as delivered. Although I'm sure Dave would still consider it !$@! poor. I wish I had seen this thread as there were several things he did that were a much better approach. I'm quickly learning to search here and that other forum for his tutorials, there is a wealth of information in Dave's post history, and he has a way of explaining and including key photos that make it very clear. I got off topic ...
The first indication of problems was the hammer jaws did not align with the frizzen. The hammer felt gritty when pulled back.
Upon disassembly I found the same problem with the tumbler. The weird shoulder around the spindle wasn't square, that caused the spindle to be canted, the grit feeling was from the tumbler grinding against the lower part of the plate and the hammer to have an eccentric rotation. I started trying to flatten the plate, and like Dave found it was ground very unevenly. I didn't realize a new one might be machined better, so I went ahead with diamond files trying to square the shoulder. After doing so it became obvious how bad a mess I was in. The boss needed to be filed just a bit so the bridle would a bit lower to slow for the lower shoulder. After adjusting the tumbler couldn't rotate, it was uneven thickness, about 1/16 thicker on the side by the half and full cock notches were. it's almost like it was ground down while sitting crooked on the plate. At this point I probably had 8 hours of careful filing, reassembling, and checking . I used a sharpie but this experience convinced my to.buy some prussian blue. I wasn't about to give up though. I set to work at truing the tumbler, when that was completed I found that the center hole in the bridle was now off because the tumbler was now sitting flat, tightening the screws caused it all to bind up. I considered welding the center hole and re-drilling, but it's such a small part it would probably warp. Instead I committed heresy. I enlarged the 2 holes for mounting the bridle so it could be shifted when tightened down. This brought everything back in line. The tumbler was able to rotate fully without binding, the bridle clearance was close enough the fly was captured, nothing was digging into the plate or the bridle, the spindle was now square to the plate. The plate still had gouges that I couldn't do anything about. I also had to stone the sear, sear spring, the end of the main spring, and the link so they would fit the now narrower gap under the bridle. The hammer also had casting boogers that had to be removed to sit flat. At this point I had about 20 hours in, I still wasn't done though. Now that the shoulder was mostly removed, the spindle stuck out too far and a large gap between the plate and the hammer looked ridiculous. I carefully filed the flats with a safe edge file and worked them down to get an acceptable stand off.
I've taken a break from the lock work, shot it several times. The hammer still isn't straight, it's better but still cocked.
It has a weird design, the hammer shaft has a notch that serves as a stop, it smashes into the plate and prevents the flint from smashing the pan. Somehow above that I need to heat the hammer shaft and bend it maybe 10° away from the barrel and also twist it slightly. I think I can clamp the hammer shaft into a vise, get it cherry red, and get a grip on the upper part of the hammer with a crescent wrench to get a little bend.
Also as Dave pointed out, the frizzen lug does pack the prime. I'm assuming this has to be the reason for my slower lock time. Last time I shot I was priming with 2f and dismissed it as that, but it is obnoxiously slow and on occasion fails to ignite despite me seeing a spark.
I suppose this means I will be removing most of the lug and grinding a notch like Dave suggested. I think I will try to avoid completely removing the lug and then fitting to remove the gap between pan and frizzen. I did that on the original T/C lock and it was a lot of work. For that one I did plug and weld the original hole, and redrill so the frizzen would sit flat on the pan, but in the end it didn't work, I still have to refresh the prime when it's wet out, and it's still no protection from rain. When it's raining I use a wax putty to seal around the lock and frizzen, and the bolster so no water runs in. I also use a cows knee. Instead of doing that I'll leave a little of the lug there so it looks tight and get the exterior polished so it looks presentable (for a T/C shooter).
I've been researching longrifles for a while now, i'd rather put my time into my first build. This experience has shown me that I will not be using L&R. It'll be either a Kibler or a Chambers lock for me.
