Cock not engaging

[dkloos]

At a recent event, my newly completely Fusil de Chasse was rendered unusable because it would not engage into Full Cock. Let me explain...
The lock is L&R, and when I put it onto half cock - it works fine. However, when I pull it back to engage it into full cock, it will click into position and then within a second it will disengage and fly forward into the fired position. (not a good thing to learn when your about to enter a 'battle'.) I took off the lock, and it appears that the notch for full cock is not holding the notch on the hammer, hence it slipps out of position and fires. Is there a way to fix this? or do I need to buy another expensive lock? Thanks! eace:

 

[Rebel]

If it is na L&R, then they should fix the problem, if you can get them to do anything.

 

[Gary]

Sounds like you need to work on the tumbler. The notch needs deepening to increase the engagement. Anneal it first to make it easier to file. After it's deepened and will hold, it needs to be rehardened. :imo:

 

[hangfire1755]

Gary,
The sear can also be the problem. If the face of the sear that engages into the tumbler notch is not hardened properly it will round off from being to soft and slip out prematurly. Check the sear and see if the edge is still square and sharp.
Don Y.

 

[dkloos]

I believe I have solved the problem. I removed the lock and examined the sear closely, and then took off a lock from one of my other flintlocks and compared how deep they were. I then disassembled the L&R lock and filed out the notch, making it deeper, but not so drastic as to need any hardening or other modifications. The lock works fine now, trigger pull is still the same, as it wasn't very deep. Thanks :master:

 

[No Deer]

These other answers are probably right one the money. However, if like me you know nothing about the workings of the lock, you would be best advised to take it to a gunsmith or someone that you know that does know how to work on them. It is too risky to mess with the lock if you don't know what you are doing,it could make a bad situation worse :imo: :m2c:

 

[Arrowstorm]

You know.. I have this same problem when I tighten my lock screws a little too tight. I can pull it to full cock, but it immediatedly snaps forward. However, when I loosen the lock screws every to gently, it just works fine and dandy

 

[rich pierce]

If you can file a tumbler it's not hard enough and that notch will round over in 1000 shots or less.

 

[hangfire1755]

This can be a few things:
1-the whole for the sear arm that is drilled into the stock might not be centered around the arm, so when you over tighten the lock bolts it pulls the lock up on an angle and the sear hit the edge of the whole preventing the sear to fully engage.
2- the whole for the sear arm in the stock itself might not be drilled deep enough so the arm bottoms out in the whole preventing free movement. When you loosen the lock bolts there is no binding.
Don Y.

 

[crockett]

On re-hardening. Is case hardening sufficient? The Kasenit can be done two ways- heat cherry red and dip it in the powder- reheat cherry red a few minutes and quench. The other method requires a longer soak time and a deeper carburization. Any opinions here?

 

[rich pierce]

case hardening is sufficient.

 

[musketman]

I believe I have solved the problem. I removed the lock and examined the sear closely, and then took off a lock from one of my other flintlocks and compared how deep they were. I then disassembled the L&R lock and filed out the notch, making it deeper, but not so drastic as to need any hardening or other modifications. The lock works fine now, trigger pull is still the same, as it wasn't very deep. Thanks :master:

Just to be sure, (WITH THE GUN EMPTY) cock the gun and press sturnly on the back of the hammer with your thumb...

Did it slip and move to the fired position?

If not, shake the unloaded gun, again, did it slip and move to the fired position?

If not, then it's OK...

I suggested this because if you are out hunting and getting ready to shoot at game, you don't want it going off while you are swinging the barrel on target...

 

[Gary]

Glad you got it fixed.

As I thought. It's not the sear but the tumbler. The sear was holding the tumbler at half-cock and the tumbler notch needed deepening.

For me, the sear is that thingy with the arm that is contacted by the trigger. The tumbler is the thingy that the hammer is attached to. So much for scientific terms.