Flint works loose after multiple shots

[CuNosecap]

Let me start by saying I agree with everything said as remedies so far (except lead) because thin leather, repositioning flint etc may quite easily fix your problem and you can move on.
But...

I have a couple of comments based on your picture. You say it is a Chambers' lock but you don't mention which one. I saw the Ketland was mentioned but not confirmed by OP. I have about a dozen Chambers sitting around and I looked at all of them (no Ketland's in the bunch though).
First question/comment:

I'm certainly not disparaging Chambers. I could have taken too much metal off in certain spots when finishing it. It's just one of those learning curves to work around.

You made similar statement in first post as well, so I looked closely, first at my Colonial Virginia lock. it has a groove in the cock matching a "V" sprue like protuberance (too defined to be a casting mark or sprue) that fits in the groove. The Golden Age locks do not have this and I suspect you have something other than the Colonial Virginia. I am guessing this V is to limit side to side wobble which may lead to a loose flint. Did your lock have this "V"? And if so, was it removed? possibly adding to the loose flint problem? The picture I loaded from your initial post now has a circle in yellow that shows some machining work was done on the bearing surface of the cock.

NWTradegunner mentioned the jaw angle too. I inspected all of mine and wonder if the hole in the top jaw is out of tolerance in relation to the shoulder bolt portion of the jaw screw. The angle on all of my Chambers locks seems to be less pronounced, but this may just be a reflection of the thick leather. I outlined the two angles in red and blue below.

I have seen this angle be affected by firing the lock without a flint, placing stress on the screw and/or the cock neck itself.

These are just other things to consider, but I suspect your fix lies in a simpler concept of too thick leather.

Rick

 

[HighUintas]

Let me start by saying I agree with everything said as remedies so far (except lead) because thin leather, repositioning flint etc may quite easily fix your problem and you can move on.
But...

I have a couple of comments based on your picture. You say it is a Chambers' lock but you don't mention which one. I saw the Ketland was mentioned but not confirmed by OP. I have about a dozen Chambers sitting around and I looked at all of them (no Ketland's in the bunch though).
First question/comment:

You made similar statement in first post as well, so I looked closely, first at my Colonial Virginia lock. it has a groove in the cock matching a "V" sprue like protuberance (too defined to be a casting mark or sprue) that fits in the groove. The Golden Age locks do not have this and I suspect you have something other than the Colonial Virginia. I am guessing this V is to limit side to side wobble which may lead to a loose flint. Did your lock have this "V"? And if so, was it removed? possibly adding to the loose flint problem? The picture I loaded from your initial post now has a circle in yellow that shows some machining work was done on the bearing surface of the cock.

NWTradegunner mentioned the jaw angle too. I inspected all of mine and wonder if the hole in the top jaw is out of tolerance in relation to the shoulder bolt portion of the jaw screw. The angle on all of my Chambers locks seems to be less pronounced, but this may just be a reflection of the thick leather. I outlined the two angles in red and blue below.

I have seen this angle be affected by firing the lock without a flint, placing stress on the screw and/or the cock neck itself.

These are just other things to consider, but I suspect your fix lies in a simpler concept of too thick leather.

Rick

Thanks for your thoughts! No, my lock didn't have that tongue and groove thing in the cock and top jaw. It is a late ketland.

I didn't do any machining work on that area. Just files and sandpaper for finishing.

The clearance of the bolt in the top jaw is quite sloppy. Lots and lots of room. The top jaw hole isn't really drilled crooked .... The clearance just allows the jaw to sit at that angle in the screw.

 

[CuNosecap]

Chambers parts aren’t cheap, but they are available. I have replaced jaw screw and other parts, so know if the leather trick doesn’t work, Chambers can get you back to shooting.

 

[Rob M.]

My flint keeps working loose after multiple shots. I even used a graver and raised some teeth in the top jaw so that it grips the leather really well. And I crank the screw down as tight as possible without feeling like I'm going to damage my lock. It is terribly annoying. I have to reset the flint and screw every 7-8ish shots.

Can anyone see from these pictures why it's happening? Is it the angle the top jaw is sitting at in relation to the bottom? Did I take too much off the back side of the top jaw when finishing it? The latter is my worry because I don't feel like having to fix it.

View attachment 316799View attachment 316800

Yeah , I hate when that happens ! Two things ... Try to get flints that are fairly flat on top not that slope , I know , it ain't easy , a lot have that slope , I separate my flints according to the slope and flat toped ones ....and try lead , hammer flatted round ball cut to long rectangle , instead of the leather ... Smart of you putting the " teeth " in the jaws. ... Best of luck .

 

[Doug Fay]

It's a chambers lock... But I wasn't going to do any wailing and tooth gnashing! I figured it's something I did when finishing or wasn't doing correctly in use.



Thanks for the replies and advice, all! I'll try getting some thinner leather and putting the flint up against the screw.

Although, I thought that with a correctly built lock you should be able to move the flint forward as it wears to get more life from it. Is that not correct?

Also make sure that the screw hole in the top jaw is properly shaped and sized and the edges are smoothed so it is not binding against the screw when you try to tighten it (note how the top jaw is slanted, and not perpendicular to the screw). If it is binding, then a lot of that torque you apply is to overcome the binding and not actually tightening the jaw against the flint. I had that problem with my pistol. A little rat-tail filing fixed it.

BTW I found that thin suede leather I bought at a local craft store works really well. It's about 1/16th inch thick.

 

[HighUintas]

I cut a strip from some old thin leather gloves, putting a couple holes in it to put the screw through and let the flint rest against the screw if needed.

I used a fairly worn flint that was shorter and broke on one side of the edge so had to flip it over after a bit of shooting. But I got through 25 shots without having to tighten it adjust the flint due to the jaw loosening, so I'd call it a success! Just had to flip the flint due to it being nearly used up

 

[MAC1967]

The leather looks thick. I find it works best with thin flexible leather.

Don

My first thought too - leather looks thick. . .try something a little thinner.