Set trigger problem

[28659]

I took my flintlock to the range today for the first time. I found that
when I set the rear trigger and pulled the front trigger the cock would
only fall to the half cock position. If I cock the lock and pull the front
trigger the lock will fire. I removed the lock and it seems to work
perfectly in my hand. Can I assume the problem is with the trigger?
I know nothing about set triggers and I am reluctant to mess with it
without instruction. Does this sound like an adjustment issue? Since
I had driven 40 miles one way to get to the range I decided to take
a few more shots using the front trigger only. On my second shot
the front sight fell off. I found it in the grass and was able to replace
it with my fingers. It is so loose it will fall off just by tilting the barrel.
Is there some way I can use this sight or do I need to buy a larger
one and file it to fit? I thought I could put some solder in the dove
tail and then file it until the sight fits tight. Would that work? I have
built a couple NW trade guns but I am a newbe to shooting. Needless
to say I did not have a good first day at the range!




d
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[Erzulis boat]

There are many different types of set triggers, but nowadays most work on a similar principle.

Your set trigger seems to be able to discharge the arm whether set or unset. Aft of the halfcock notch is the sear notch. When you pull the trigger without setting it, constant upward pressure is applied by the attendant triggerbar. This allows the sear to remain clear as the tumbler rotates. Remaining clear, the nose of the sear will not enter the halfcock notch.

The "set" mode however acts on a different principle typically. A trigger bar is released under pressure and snaps upward very quickly, thus tripping the sear. But unlike the trigger bar that maintains pressure on the sear to clear it, the set trigger bar just impacts to trip the sear without sticking around to hold it.

The tumbler that is designed to be compatible with this type of set trigger has what is called a "fly". The fly is located on a pivot adjacent to the halfcock notch. The fly is unidirectional in application. When you cock the arm, the fly pivots allowing the sear to engage either the halfcock notch or the sear notch.
But if the arm is fired the fly will rotate and allow the nose of the sear to override the halfcock notch, thus allowing the arm to discharge.

This sounds like you are either having a problem with the fly, or one is not present.

This might be an easy fix.

:thumbsup:

 

[Erzulis boat]

Since you already stated that you removed the lock to inspect it, you might as well do it again.

Place the lock in your hand with the internal mechanism facing you and pull the cock to the rear. Rotate the frizzen clear, and with the cock under control, trip the sear. Allow the cock to come forward a tiny bit, just enough to clear the sear notch but without allowing it near the halfcock notch. You will see that if you let the sear come back into contact with the tumbler it will want to enter the halfcock notch.

If there is a fly, it might look just like a tiny necktie on a little pivot. It will be located at the halfcock notch area. If it has a fly, then allow the cock to come forward some more (under control!) you will see that the sear nose will ride over the fly and allow the cock to complete its rotational cycle without you having to apply pressure to the sear.

If there is a fly present, and this test checks out, the trigger mechanism might be at fault. If the test fails, but there is a provision for a fly on the tumbler, you are OK. A provision will be a little post within a shallow channel.

If there is no fly and no provision for one that might be a problem. But check it out first.

What is nice about this hobby is that fixing things is pretty easy, and can be done yourself.

 

[Erzulis boat]

I almost forgot!

Once you have the lock off, leave it off until you get more input from other guys on the site.

There are a ton of real experts out there with decades of experience.

:thumbsup:

 

[Stophel]

What kind of gun is it? It almost sounds like you have no fly (or it is improperly shaped to allow the sear to go over the half cock notch). It definitely sounds like you ain't got enough gumption in your set trigger spring.

Oh, the sight. Assuming you have a brass dovetail, you can remove the sight, and peen the sight base a little bit to spread it out until you can get it to fit tightly in the slot.

 

[Zonie]

As the others have said, your fly is either missing, rusted in place or so contaminated with oil or some small chip that it cannot rotate properly.

The used GPR I bought a few months ago did not have a fly in the tumbler. I don't know if it came from the factory that way or someone removed it.
Anyway, Lyman sold me a new one for a few bucks and everything worked out fine.

As for the sight, you need to make a few burrs by denting something.

As you have found, the sight is located on the barrel with a dovetail and this makes the fix relatively easy.
You can remove the sight and place it on a hard surface or in a vise with one of the little angular surfaces up.

Use a small hammer and a screw driver or some other moderatly sharp bladed tool to put a few dents in the sharp edge of the dovetail where the little angular surface meets the bottom. Repeat this on the little angular surface on the other side. Then lightly tap it back into the female dovetail in the barrel.

If you don't want to make a burr on the sight base, you can also use the same method on the sharp edge of the female dovetail where it meets the top flat.
If you do this, you must make the dent exactly where the sight blade will be located so it covers up the dented area.

It doesn't take much of a burr to make the dovetail lock as it is supposed to.

For more information about FLYS, follow this link;
Zonies Fly Fix on his GPR

 

[2172]

I'm going to guess you are shooting a GPR. I had this problem with mine, and I've seen the problem on the board here, several times. I got all of the suggestions you're getting, and tried them all...what did work for me was to remove the sear spring, that little coil spring in the "tube" to the rear of the lock, and snip off a half turn...that fixed it...try it..Hank

 

[28659]

No Hank, its a southern mtn rifle with a large siler lock. I took the
lock apart and removed grease from the fly and the other parts,
put it back togather and it still malfunctions. It looks to me like
the fly is a little too long. When I operate the lock slowly by hand
it kinda wants to stop at the half cock notch. I thought about filing
the fly off a little but I am hesitant as I don't want to make matters
worse if this is not the problem. I welcome any suggestions!

 

Contact Jim Chambers - www.flintlocks.com. Ask him what to do. I have a fly issue with my lock (the opposite of your issue, mine doesn't want to push the fly out of the way to engage the half-cock notch), and he is having me send it back for him to fix.

 

[hwalker]

Check the fly, in my L&R lock, it's designed to work only one way, but it is possible to put it in backwards/upside down. If the fly is put in incorrectly the angle on the fly is wrong and won't work as smoothly or maybe not at all.

 

[Zonie]

Roamer: The flys in a Siler lock are impossible to be put in backwards.
They have the pivot shaft cast into them, and it fits into a hole in the tumbler.

You make a good point for those who have L&R locks though.
Some of their locks have a fly which is a small plate which fits on a small post that's cast into the tumbler.
It is possible to put them in backwards and they won't work properly if that's done.

The fly's in a Siler lock is a small investment casting which only requires finishing on the point that serves to keep the sear from engaging. If this is not finished properly, it can cause the problem which was mentioned.

This fly by the way, is hardened. A file will not cut it. If you want to remove any material from it, a good whet stone is the best thing to use.

If Jim Chambers will look at your lock and repair it, that's the best way to go.

 

[28659]

I finaly discovered what the problem was. It was the sear. there is a
small chip out of it where it passes by the fly. I have a new one
coming from chambers. Many thanks to those of you for helping
solve this problem.

 

[Old Dave]

I'v had this problem on a few rifles over the years and the most common fault is the sear ,when struck by the trigger ,could be flying up and hitting wood and bouncing back down ,over the fly into the half cock notch . remedy'''releave wood in sear hole above sear in mortice . to check , blacken sear put back in gun ,set er off then remove lock then check top of sear hole for black ,if it's there you know it's hitting good luck old dave

 

[Zonie]

Man who says Huh? That makes sence. The sear is very hard, which also makes it very brittle.
It should be tempered to remove some of this brittleness.

If it was left too hard, I can see where the hard nose of the sear could chip when the fly/tumbler is impacting it.
Obviously it is supposed to jump over the half cock notch when this happens but it wouldn't take a very large chip out of it to make it fail to jump.

Have a good one!