Hi Bob,
I have one and it seems to be a pretty good lock. The small English design is fast but because of the short throw of the cock not because of the fly position. The fly sits in a slot in the middle of the tumbler and pivots on a pin through the tumble. It is a very strong design and it contacts the center of the nose on the sear rather than one side. That likely reduces risk of the sear chipping on one side where it rides over the fly. In my opinion, it is probably a better design but not essential by any means. The lock uses the old cast spring from either the L&R Durs Egg or Bailes lock. On mine, the sear screw threads in too far and pinches the bridle against the sear. I will replace that screw. I do not like the size or orientation of the sear spring. The upper leaf is oriented horizontally rather than parallel to the tail of the lock plate. That means the bend is right at the edge of the tail of the plate. Consequently, you cannot shorten or reshape the tail. If the spring was parallel to the edge of the plate, you could shorten and reshape the tail end to create a better pistol lock. I suspect in performance, the lock is no better than Chambers classic Ketland or Kibler's late English flintlock. It does have the fence separated from the pan, which is a nice feature. Assuming the stirrup is properly heat treated, I would not worry about its strength and it does provide mechanical advantage a little like a compound bow. As far as copying an actual lock on a Nock gun, the similarity is somewhat superficial. They used parts from some of their other locks and designed some new ones. However, the quality of assembly and finish is not up to the best English locks. I have a mid quality late flint English fowler and the fit and finish of the internals on that lock are superior to the Rice lock.
dave
Actually I did see this lock at the CLA Show in Lexington and again at Friendship at the Fall shoot.
I thought the mainspring was too close to the lower edge of the plate and the tumbler arm looked
too thin when the strength of the spring is considered.the chance of a sear catching the edge of a
tumbler if the fly is right is zero IF the sear is on a precisely fit screw or smooth pin and can't
go into an angle on the way down
The Nock influence is much stronger and almost identical in the locks I sent to Helmut Mohr in
Germany and is close in appearance to the current L&R small Manton.I had an original Nock from
Lynton McKenzie and I was really surprised at how closely it resembled the lock I was just starting
to make for Mohr.These were made from old dies to make the cock,frizzen and plate.There were were
internal parts available but I thought they were flimsy and rejected them in favor of my own parts
and these have been in use for over 40 years now.
I did try to maintain a good level of finish right up to the last locks I made which were two flints based
on the external parts of th L&R Durs Egg,a Hawken with a plate and hammer reproducing a J&S lock
and a "Bridger"style with a "3 pin"English style mechanism.Not traditional but slick working and ONE of
a kind
.
Right now all I want to do is make some double set triggers for Hawken and lighter rifles and that is IT.
Bob Roller