Author Topic: Cock peening the lock plate  (Read 4193 times)

Offline curly

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Cock peening the lock plate
« on: August 12, 2015, 02:18:47 PM »
I have a flintlock that has only been dry fired (with a flint) maybe 5 or 6 times and already the lock plate is noticeably preened to the point that it has to be filed from the face of the lock.  I was thinking about milling the bolster down about 1/16 to
3/32" and soldering on a piece of tougher steel. I'm concerned about warping the lock plate so any suggestions would be greatly appreciated. Thanks in advance.

Curly

Offline Acer Saccharum

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Re: Cock peening the lock plate
« Reply #1 on: August 12, 2015, 02:59:31 PM »
Often a case hardening will help prevent that issue. 

If the cock can be moved closer to the plate to increase the contact area, that will help a lot. This is done by filing the square on the tumbler, and then re-fitting the cock.

Fit the contact area between cock and plate shoulder, by filing down the high spots., using Prussian blue, carbon paper, or hi-spot blue A good fit will spread the impact over a wider area, reducing the peening effect.
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Offline curly

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Re: Cock peening the lock plate
« Reply #2 on: August 13, 2015, 06:21:10 PM »
Thanks Tom. I actually did everything you suggested, but the problem of distorting the plate, just by 4 trips of the lock, still peened it noticeably. I filed it smooth once more and took a small piece of old exacto blade I had and soldered it to the top of the bolster. Filed and cleaned it up and it solved the problem completely. I dry fired it at least 15 times with no distortion what so ever. Thanks again for the reply Tom.

Curly

Offline jerrywh

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Re: Cock peening the lock plate
« Reply #3 on: August 13, 2015, 07:39:54 PM »
 The proper way to fix the problem is to case harden the lock.
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Offline David R. Pennington

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Re: Cock peening the lock plate
« Reply #4 on: August 13, 2015, 10:49:15 PM »
I fitted up the last lock I built so the tumbler hits the bridle same time as cock hits plate. This seems to distribute impact. Last plate I casehardened warped a little and had to refit everything slightly.
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Offline P.W.Berkuta

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Re: Cock peening the lock plate
« Reply #5 on: August 14, 2015, 12:30:03 AM »
This is how I do all my locks ;). When done correctly the force is distrubited at different points of contact. If some say "what about when the internal screws are left loose so as not to cause binding when tightened" I say that the lock needs to be fixed - the screws SHOULD shoulder up to the plate without binding the internals allowing them to move freely - make new screws if necessary.
"The person who says it cannot be done should not interrupt the person who is doing it." - Chinese proverb

Offline Bob Roller

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Re: Cock peening the lock plate
« Reply #6 on: August 14, 2015, 01:10:46 AM »
I have a flintlock that has only been dry fired (with a flint) maybe 5 or 6 times and already the lock plate is noticeably preened to the point that it has to be filed from the face of the lock.  I was thinking about milling the bolster down about 1/16 to
3/32" and soldering on a piece of tougher steel. I'm concerned about warping the lock plate so any suggestions would be greatly appreciated. Thanks in advance.

Curly

Years ago I made brass plate flint lock and dovetailed a hardened and tempered insert into the area struck by the cock. I also made sure the cock was close to the plate.I also used a precision steel bushing for the tumbler to turn in.

Bob Roller

Offline smart dog

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Re: Cock peening the lock plate
« Reply #7 on: August 14, 2015, 01:42:51 AM »
HI Curly,
The plate needs to be case hardened.  Depending on the carbon content of steel in your lock plate, you may be able to harden the plate without resorting to a case-hardening procedure.  All the other suggestions may work temporarily, but once there is some wear on internals and the plate, it will be clear that hardening the plate is the best solution.

dave 
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Offline jerrywh

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Re: Cock peening the lock plate
« Reply #8 on: August 14, 2015, 05:02:29 AM »
 And the hammer.
Nobody is always correct, Not even me.