flintlock lock problem

Not very knowledgeable about flintlocks, but just bought a used Pedersoli kentucky pistol and noticed that the trigger pull is very light and you can even use your finger to release the cock with moderate pressure from the full cock position. Is there somewhere I can read up on the function of the lock to try to determine what's up. Could be someone messing with the sear, or something simple. I'm guessing I need some new lock parts. At any case, it seems unsafe to me to have it this way. Any advice on flintlock gunsmiths?
Thank you,

The first and easiest thing to check, is take the lock out of the stock and see if it is still too light. If not, it is a wood to metal fit, or trigger issue. If the problem persists with the lock out of the stock, check the sear spring first to see if it is installed correctly with the screw all the way in, and the little tab properly in the slot of the lock plate. If this is all as it shold be, and the problem persists, it is probably a problem with the fit of the sear to the tumbler. It could be due to wear (probably of the sear notch), breakage (probably of the sear nose) or someone with a file made it better. Check to see if you can identify which of the above looks like it, and let us know.

Well,, so far the wood/metal factor seems not to be the problem. Even out of the stock it's light and touchy. The sear spring is in place. I think it's the full cock groove, or sear nose that's worn,, but hard to see the way it's made with a cover plate over all these pieces. Since I don't have the correct tools (spring vice) and don't have a good working knowledge of the locks mechanical workings yet, I need to do some more reading. Thanks. I let you know when I've come to a conclusion or if I find a muzzleloading gunsmith.

If you have a double set trigger with the little screw between the two triggers, after you clean things up, you may want to back that screw out one full turn (counter-clockwise) and see if that makes a difference.

As it's turned "inboard" it raises the trigger bar(s). Turned in too much and now it's starting to "trip the sear" before you even touch the trigger.

A simple way to set up that screw is:

With the lock in the "fired" position, so hammer down, set the triggers and slowly start turning in that screw (clockwise) until the "trigger" fires.

Then back it out 1 (one) full turn and it should be "fine/functional".

If you want to fiddle with it from that point get some good instructions on how to adjust/tune triggers and piddle around.

But the simple setting I noted above should get it working both safe and functional.

Graham, It's a single trigger. But thank you for that technique for setting up a double set trigger.

You have a geometry problem in the sear to tumbler notch angle. You should not be able to push the cock to release even with no sear spring at all. You will have to do some careful stoning on the sear nose, or the tumbler notch to correct it.

Thank you sir. Sounds like something I should have a gunsmith do. I suppose if I could find a new sear/tumbler I could install those without much difficulty. But I am not that experienced to do any stoning. Unless I just need to deepen the full cock notch on the tumbler.

Really, what Wick said is good advice. Just take the lock out and study it and how it relates to placement with the trigger. Without picking up tools, just activate the lock. You will learn much by doing this yourself. Re-read Wicks advice and soon you will be able to make that adjustment yourself.

If you are unsure of what you are doing, take the lock to someone who does know how to fix your problem.
Once the lock is done correctly, study the internals of the lock. Pay attention to the sear/tumbler relationship. It is important to have a safe lock. No accidental discharge.

To get what is needed, you want the face of the tumbler notch at the angle of a straight line from the center of the tumblers pivot shank/pin, and the sear nose to match, at full cock. It can be good if you have maybe 1° over that line angle to assure safety, but either way, you should be able to set the sear in the notch with no sear spring at full cock, and not be able to make it release with reasonable pressure on the cock. Both the sear face and tumbler face should be polished reasonably bright. This entire job can be done with diamond files, even the cheap ones, and automotive sand paper glued on popsickle/craft sticks to polish with. You must take care to not round the surfaces though. They need to be as flat as you can get them.

A sear spring that is screwed down too tight or a sear spring with too little pressure on the the sear can cause a fault like that.

My next check would be the full cock notch on the tumbler and how the nose of the sear engages the full cock notch.

Those would be faults on the lock itself. Any unwanted contact between the lock inlet and the lock or the trigger could also cause problems.

I've ordered a mainspring vise to get to a point where I can view this better. The bridle is made to cover the nose of the sear and most of the tumbler, so I can"t see what I need to see. But I sure appreciate this lesson I'm receiving about the lock. It's great.

Most of these locks that I have seen have the opposite problem of being way too heavy. Is it possible that someone has "fixed" this lock and maybe gone too far?
Another problem that occurs over time is that the sear nose bumps the halfcock notch and eventually wears the end of the sear into a rounded shape. Give the sear nose a good close look. You may need a replacement part.

Do the makers (pedersoli in this case) have their own proprietary parts (sear and tumbler) or can you buy generic parts such as these two.

It would be best to buy replacement parts from Pedersoli. However, don't expect them to be any better than what you have. They very likely will still need final fitting to be optimal, if they are even close.

what Wick said is, regrettably, quite true ... you should probably consider buying a few spares (in case you mess up one of them, or in case one just flat wears out) since many of these parts cost more to ship than the do to actually purchase. (since you're 'shopping,' see if your lock has a flye - this is the tiny little doo-hickey which prevents the lock from dropping to half cock is a double set trigger is used... get three, and put them in an well marked envelope ... don't ask me how I know)
:cursing: :redface: :redface: :redface:

give the folks at Track of the Wolf a call - I can't remember if they carry Pedersoli locks, but they may be able to point you in a good direction.

good luck with your project!

Thanks MSW. She does have a fly.. :thumbsup:

Update: After getting my mainspring vice, I dissembled the lock. The problem looked to be the full cock notch. It's profile was much shallower and angled slightly backward as compared to the half cock notch. I used a fine V-file to renotch and shape the full cock notch to resemble the half cock profile. I then used finer and finer stones to smooth the steel. After reassembly, which was tough with that smaller pistol mainspring, she is no longer allowing me to overpower the cock at full cock. Trigger pull is a little greater as I expected, but I seem now to have a safe pistol. Thanks for all the help.

And.....now you have a better understanding of your lock's internals and functioning.

There is the trouble right there, a file should not touch a properly hardened full or half cock notch. If it does it is just a matter of time before it will start slipping off again.
When the steel is not properly hard this is a perpetually changing engagement that is not very safe.
If it were mine I would re-harden by casing, through hardening (depending on steel type) or building a new one out of A-2 or O-1 tool steel. Mike D.