My trade gun

[Riley/MN]

So I wasn't sure to put this in "Flintlocks" or Smoothbores", but since I am going to talk about the lock, it is here. I bought a trade gun off ridjrunr about a year ago I guess. I sent the bbl in to Danny Caywood about a week ago to get it jug choked - gonna slay some turkeys!

Anyway, I did take it out last spring for turkeys, and I noticed that it could fire from the half-cock position. I decided to look at the lock while the barrel is away on vacation...

I have found in the little bit of searching I have done that the Lott lock is representative of a trade gun lock, but not really a copy of any particular lock (please correct me if you know better, cuz this is uncharted territory for me)
[attachment=2:1iajmvw6][/attachment]IMG_20150220_071147915.jpg[/attachment:1iajmvw6]

I noticed the sear & tumbler don't mate up very well at half cock.
[attachment=1:1iajmvw6][/attachment]IMG_20150220_070615260.jpg[/attachment:1iajmvw6]

I also noticed that they just barely catch at full cock, but that does not seem to be a problem.
[attachment=0:1iajmvw6][/attachment]IMG_20150220_071021954.jpg[/attachment:1iajmvw6]

So, not having ever worked on a lock before other than stoning a surface or two... Do I need to reshape the nose of that sear?

[rollingb]

It's kind of hard to tell from the pictures, but the half cock-notch should be a bit "undercut" rendering it very difficult to fire using the trigger. If the half-cock notch is undercut and the nose of the sear isn't fitting in the notch properly, someone probably has altered the sear nose.
Two things you can do,... make the half-cock notch fit the nose of the sear, or make the nose of the sear fit the half-cock notch. Personally, I have an aversion to messing with the nose of any sear (unless it has already been messed with), and would prefer to concentrate on the half-cock notch itself.
I think some of the Tryon Trade Gun lock parts will interchange with the old (Pedersoli) LOTT lock, but I'd have to check on that if thinking about getting a new sear.  

[Riley/MN]

Yeah, I was thinking about removing the bridle to see if I could get a better picture.

Right now I'm working on Jeep problems though (researching on Jeep Forum) - Looks like I won't make the trade fair tomorrow...

[Brent Gurtek]

Riley,
It looks as though both the sear nose & the 1/2-cock notch each have an issue. The notch has a sort-of melted away look; either from wear &/or breakage. And the sear nose appears incomplete.  Both of these malformations will cause slipping of the sear off the tumbler.
Also, there seems to be a burr of pushed up metal in the root of the 1/2-cock notch, as though the sear bar recieved a heavy impact when the lock was half-cocked.  If so, that could explain some, or all, of the anomalies.
Regarding the authenticity of this lock for the typical English Northwest Trade Gun, the canoe-length example I made as a demonstrator for the North House gun making class has the Lott lock.  And based on Ryan Gale's really great Trade Gun book there is quite a bit more variation in these Trade Guns than we usually realize.  It seems that virtually any round-faced lock, 5 3/8" to 6 1/4" was used.

[gunmaker]

Can you cut the sear or tumbler with a fine little file ?  Hard to see with bridle on there, but they are both worn down---or messed with.  If you have a good quality lock on hand look at the parts in it, they should be sharply defined, not rounded over.....2CW...Tom

[Brent Gurtek]

Good ideas Tom. That would be the first approach to remedying the problem.