Author Topic: Percussion lock main spring screw  (Read 466 times)

Offline Limestone

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Percussion lock main spring screw
« on: December 13, 2023, 10:23:56 PM »
 Hello, I am putting a lock together, the screw for the main spring is 8-32. It threads into the lock plate fine, when I try to go thru the main spring hole it binds up. I am thinking of opening up the hole in the main spring using a small round file. Could I cause any issues to the spring? I don't believe I need to remove much material. Thanks

Offline Eric Krewson

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Re: Percussion lock main spring screw
« Reply #1 on: December 13, 2023, 10:54:26 PM »
What kind of lock is it, mainsprings don't usually have a hole in them, sear and frizzen springs do.

Offline JTR

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Re: Percussion lock main spring screw
« Reply #2 on: December 13, 2023, 11:29:56 PM »
Early flintlock main springs often have a hole for a screw.
Opening that hole a bit shouldn't cause a problem. 


John Robbins

Offline Limestone

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Re: Percussion lock main spring screw
« Reply #3 on: December 13, 2023, 11:32:10 PM »
The lock is an M1842 Springfield. It has a small alignment pin that goes into the plate. The top of the main spring closest to the trigger sits under a small shoulder, and the screw keeps the spring tight to the lock plate. The other leg of the main spring rides on the tumbler. A picture would better describe it, but no camera. Thanks for both replies.

Offline Eric Krewson

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Re: Percussion lock main spring screw
« Reply #4 on: December 14, 2023, 05:34:53 PM »
I learn something new every day.

Like was said; enlarging the hole shouldn't hurt a thing, they are not the least bit fragile, I have filed on a bunch of them that were rubbing on the lock plate and haven't hurt one yet, I did bring where I filed to a mirror finish after I finished filing.