bigted said:
So in retrospect...
The frizzen. Almost always hangs instead of snapping fully open. Is it possible to have too stiff a frizzen spring? I see you tubes where as soon as the flint falls the gun fires, fast as a capper, not so much with this Davis old English lock...
I do like dinkin with it but seems like im in a hard spot here.
When you say the frizzen "almost always hangs" does the flint remain pressing against the frizzen face or, is the underside of the frizzen resting on top of the flint?
If the flint remains with its edge against the frizzen face that can be an indication of a weak mainspring, poor cock geometry, a frizzen spring that is too strong and/or the cam on the frizzen is misshaped or too tall.
If the lock were mine, I would remove the frizzen spring and try cocking and firing the lock with the gun unloaded.
If the flint still hangs up on the frizzen face, the problem is with the cocks geometry.
If it doesn't, the problem is with the frizzen spring or the frizzen cam.
Assuming the flint did not hang up I would first look at the small cam lobe on the bottom of the frizzen.
This will sometimes have a irregularity in the casting causing it to be too tall or to react with the spring poorly.
Smoothing the tip of the cam and reducing its height a little might fix the problem.
Because the frizzen is hardened, this cam repair is best done with a whet stone.
If smoothing and slightly shortening the frizzen cam doesn't fix the problem the next step would be to reduce the width of the frizzen spring.
The amount of change on the spring is a direct function of its width. If the width is reduce 25% the spring will be 25% weaker.
I wouldn't go over about 50% maximum reduction.
A sharp new flat file, a whet stone or a few sheets of black silicon carbide sandpaper backed by a hard flat surface can be used to reduce the spring width.
I do not recommend using heat to modify the frizzen spring.
Heat can temper the spring, causing it to be softer but this will not change the springs resistance to bending.
Steels modulus of elasticity is dependent on the material and is a constant.
(Modulus of elasticity is a measurement of a materials resistance to bending. It does not change whether the steel is soft or hard.
For those who care, the modulus of elasticity of carbon steel is 30 X 10^6 psi)
I suspect Britsmoothy's spring bent because of its soft condition. The problem is, if it bent and wasn't rehardened and tempered properly, it will continue to bend until it reaches a point where the stresses match the springs strength.
This might work fine but it also might end up with a spring that doesn't keep the frizzen closed.
Getting back to the situation where the frizzen ends up sitting on top of the flint, this happens when the flint knocks the frizzen open as the cock falls.
The (often scrolled) end of the frizzen down by the cam hits the frizzen spring and the spring knocks the frizzen back towards a closed position where it comes to rest on top of the flint.
Reducing the frizzen spring pressure can help to eliminate this but not always.
If the frizzen ends up on top of the flint, usually it doesn't have much effect on the reliability of the lock unless it is blocking off part of the vent hole in this "almost closed" condition.
