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General discussion => Tutorials => Gunmaking tools and techniques- metal shaping => Topic started by: Blackpowder Barbie on October 02, 2009, 12:58:20 AM

Title: The Quality Flintlock by Jim Chambers
Post by: Blackpowder Barbie on October 02, 2009, 12:58:20 AM
Here is a copy of the information we have about what makes a quality flintlock.  Perhaps Dad will elaborate on this soon.



There are features common to all flintlocks which must be present if the lock is to be reliable, consistent from shot to shot, and long lasting.

A.   Exterior Geometry

B.   Interior Geometry

C.   Fit and Precision – This is a must to prevent binding and wasted power, to increase speed and reliability, and for even, long wear and lock life.

D.   Polishing – Reduces friction of moving parts.

E.   Heat Treating – Most manufacturers now supply springs that are ready to use.  No further heat-treating is necessary.  The frizzen and internal parts should be hardened and tempered according to the manufacturer's directions.

F.   Conclusion – The function of a lock is to ignite the main powder charge.  Some locks do this very quickly and consistently.  Others do not.  Good locks have several things in common: good design and geometry, quality materials throughout, and precision assembly.  Most locks will ignite the charge most of the time, but only a precision lock will fire the gun reliably and consistently from shot to shot under all conditions.  A “quick” lock is certainly desirable, but, if accuracy is your goal, consistency from shot to shot means more than speed.  Precision equals consistency.  Consistency equals accuracy.
Title: Re: The Quality Flintlock by Jim Chambers
Post by: TgeorgeZ on November 17, 2009, 07:17:44 AM
Are there any BOOKS out there on locks, their history, different types, and tuning them?  They fascinate me - how they ever designed such a thing.
Title: Re: The Quality Flintlock by Jim Chambers
Post by: derringermike on March 11, 2010, 06:48:23 AM
great info,,,anything like this for percussion locks? I'm building a single shot percussion deringer from scratch...any help would be thanked   mike
Title: Re: The Quality Flintlock by Jim Chambers
Post by: Artificer on March 13, 2010, 12:11:13 AM
Miss Barbie,

Thank you very much for posting this.  Very informative.

I've got three additional questions.

How much distance should there be from the bottom of the sear and bridle screws to where they contact the bridle?  No more than two or three thousandths of an inch?  I realize you have to custom cut the screw thread to do this.

Second question, how much distance should there be between the bridle and the tumbler post and the bridle and the top of the sear?  I'm thinking two or three thousandths of an inch? 

Third question,  how do you tell when you have a good "tip over"point on the bottom of the fizzen where the frizzen spring engages it?   

Thanks for any further information.
Gus Fisher

Title: Re: The Quality Flintlock by Jim Chambers
Post by: D. Taylor Sapergia on March 18, 2010, 10:21:19 PM
Gus, your first two questions sound like clearance/contact questions.  The bridle screw(s) that hold the bridle to the plate should be tight.  The sear screw should also be tight, but should not pull the bridle down onto the sear, impairing it's travel.  Most commercial locks do not provide for this, so I just put the screw into the drill press chuck and with a file ground safe on the thin edge, I dress down the inside face of the screw, checking often so that when done, the screw bottoms in it's threaded hole in the plate, but the sear still is able to rotate freely.  It doesn't matter to me how many thou that is - I don't measure it.
The bridle keeps the tumbler and sear rotating in a flat plane, parallel to the lock plate.  So dress and polish the inside of the bridle so that while the bridle screw(s) hold the bridle tightly against the plate, the tumbler and sear can rotate freely.  Too much, and you may have detent issues...too little and the tumbler and/or sear will bind.
Title: Re: The Quality Flintlock by Jim Chambers
Post by: northmn on March 26, 2010, 04:53:38 PM
Great info.  Acouple of points for discussion:
I really have little problem #7 Exteriror As to the pan cover projection I feel you are positively correct, but they do help hold in the primer for carrying if the fit is not tight as possible, using 4f. If the fit is atrocious they do not do that.  I will state that I ahve an older Siler Chambers lock that has a very good fit.
Long throw:  Late English locks used a stirup, strong mainspring and shorter throws on the theory of increasing lock speeds.  They also may have used smaller flints.  Is the longer throw also a means of using a larger flint which in itself is more reliable? 
I had to balance two locks for frizzen spring mainspring balance.  It is a bit tedious, I would go so far as to call one a B---h.  In one case it was a matter of slowly lighteneing both springs as the lock would destroy a flint in a couple of shots.  In another I installed a "roller" in the frizzen to get enough tension so that it would spark.  Both worked.    I have bent a lot of hammers to get the things to perform correctly in the earlier build days with Italian and some American made locks.  Thank heavens for outfits like Chambers.