I've used a lot of Siler and L & R locks. To my mind, Silers require less fussing/tuning to make them work perfectly. My biggest issue with L & R's and I have written to the firm with photos, is they grind the contact end of the sear spring so that it is too short, and pushes down on the sear a considerable distance back of the optimal point which is directly behind the pivot boss. This involves heating the spring red, straightening it out flat, filing a taper both in width and thickness to the working part of the spring, re-heating and bending the spring a little closer to the front end to lengthen the lower arm. While I'm at it, I close the bend considerably and give the lower limb the correct amount of pre-load. Then it's polish, harden and temper. Another issue, and one can find this on any of the popular commercial locks, is the sear screw is threaded too far up the shank so that it doesn't bottom against the plate while still leaving the sear to rotate without jamming. This can be adjusted by reducing the thickness of the screw's head on the inside of the head next to the shank so that the threads bottom against the plate at the same time the head bottoms against the bridle, while the sear is still free to revolve.
I haven't had the pleasure of working with a Kibler or Laubach CNC machined lock yet...looking forward to that.
