Flintlock geometry

[Columbus]

Haven't done much work on locks and I just picked up this rifle that has a Davis Jaeger and am wondering if the cock geometry is off. To me it seems to overtravel a bit. Any flint long enough to strike the upper part of the frizzen curve will hit the pan at the end of travel. Shorten the flint up to where there is clearance at the pan and the top screw hits the frizzen. I have a box of flints on hand but only a couple fall between the two extremes. As you can see in the picture - even now the flint is just a hair away from touching. The only flintlocks I've owned were imports and none were like this.

 

[jerrywh]

In order to completely understand flintlock geometry I believe a person need to make a few flintlocks from scratch.
It's not just geometry but spring balance and understanding the type of steel needed for the components.

 

[Larry (Omaha)]

Haven't done much work on locks and I just picked up this rifle that has a Davis Jaeger and am wondering if the cock geometry is off. To me it seems to overtravel a bit. Any flint long enough to strike the upper part of the frizzen curve will hit the pan at the end of travel. Shorten the flint up to where there is clearance at the pan and the top screw hits the frizzen. I have a box of flints on hand but only a couple fall between the two extremes. As you can see in the picture - even now the flint is just a hair away from touching. The only flintlocks I've owned were imports and none were like this.

Photo is from Track of the Wolf. I know nothing about what Jaeger geometry is suppose to be, but from what I see and you describe, something is not right. The cock seems to be positioned too far clockwise with respect to the pan. That of course will cause just what you are experiencing.
Flintlocklar

 

[Phil Coffins]

I’ve asked this type of question from time to time and have never gotten a clear answer. There appears to be no science to them. To build one you would need a few basic ideas on angles, lengths, spring strength and a host of details I should think. Not wanting to apprentice my self to a master in order to be able to make a few adjustments to a lock with issues I guess I’ll never improve a flintlock that doesn’t work well.

 

[Zonie]

From what I see in picture #2, the flint doesn't look right.
The edge of the flint seems to be about 1/16" above the bottom of the flint. On most, if not all of my flints. the bottom is straight and the edge is formed where the bevel meets the bottom of the flint.

As far as where the flint hits the frizzen, none of my flintlocks allow the edge of the flint to hit the frizzen over 2/3 of the way up to the top of it.

Are you getting a good shower of sparks when the lock releases? If so, maybe just getting some better flints would solve the problem.

 

[Rifleman1776]

I have had a rifle with a Davis Jaeger flintlock. The geometry was off. I complained to Davis and they agreed to SELL me a restyled cock/hammer. Current locks should have the improved style. How old is your lock?

 

[Columbus]

I have had a rifle with a Davis Jaeger flintlock. The geometry was off. I complained to Davis and they agreed to SELL me a restyled cock/hammer. Current locks should have the improved style. How old is your lock?

I don't know how old the lock is - just bought the gun last week. I did see that they offer a redesigned cock on their website. Interesting.

 

[TreeMan]

Use some thinner leather or cut the leather into two pieces. One for top and one for bottom of flint. That’ll move your flint back enough that it doesn’t appear to overtravel so much. That flint also looks huge. Is it the recommended size? The flint also doesn’t have to hit the very top of the frizzen. Some of mine hit around halfway and work just fine.

 

[Bighorserider]

Not an expert here. I only have a couple of flintlocks, but my understanding is that the flint should point at about the center of the pan when it's forward. Yours is about the forward edge of the pan. Someone correct me if I'm wrong.

 

[dave_person]

Hi,
I probably have enough experience building and tuning locks now to write a book. I also own the same lock, Columbus. The geometry is poor but also realize that in lock geometry, there are numerous ways to skin the same cat. First, the short answer for you is to use a shorter flint. However, if you note, the current long flint hits pretty low on the frizzen face so turn your flint over with bevel down particularly if you use a shorter flint. In your current configuration, the edge of the flint is right in the flash from the vent and a wide flint risks hitting the barrel. Bending the neck of the flint cock up a little will help as long as you use your flint bevel down. I solved this problem for this lock by positioning the flint bevel down and soldering a thick high-carbon steel sole on the face of the frizzen. I had to file the fence back a little to clear the extra frizzen thickness but the result was very good. There are several Davis locks, which have lousy geometry and anemic springs but they can all be made to work well. The alternative flint cock does not change any of the geometry, just the style of the cock. Track of the Wolf marketed that cock and this lock on their "Edward Marshall" rifle kit. Anyone actually familiar with the original rifle knows the Davis jaeger lock bears no resemblance at all to the lock on the Edward Marshall rifle.

dave

 

[EC121]

Here is my lock. It is on my Hill Pearce rifle from the 1980s. It has the same geometry, but I never noticed it being very bad. I shot matches with it. Another fix is to put a wedge shaped shim under the flint. That gives it more of a slicing action, and put the flint more to the center of the pan. It also prevents the strike line from forming as quickly..

 

[M. De Land]

I fixed a flint pistol with a similar problem by heating and bending the Cock upward a few degrees and recasing it for strength. It won't take much but will make the flint strike higher on the frizzen and give more clearance at the bottom. Don't go to much or you'll wind up with a flint breaker. A wedge under neath the front of the flint on the lower jaw (with some trial and error) will give you a good idea of how much to bend it upward. Be careful to keep the cock jaws parallel with the cock arm and square to the frizzen face.
Another helpful thing is to learn how to knap your own flint then you don't have to be concerned about bevel up or down because they won't have a ridge if not made from blades and flakes are used instead. I can't tell you how handy it is to shape a flint just how your gun preferres them.

 

[Rudyard]

The Davis and Chamber & Larry Zornes all have or had this feature but there fine by me The Davis Twigg is the most elegant lock offered but that depends on use & taste .
Rudyard

 

[Burlewd]

I have a Northwest trade gun. I am looking for a mainspring. Any ideas where to get one.

 

[Grenadier1758]

Are there any markings on the lock? That might give a clue as where to start looking.

Go to the Track of the Wolf's web site and download and print the full sized lock copies of their NW Gun locks and some of the large musket locks. See if any of those locks comes close to your lock.

My Hawken copy that I built using a supposed Cherry Corners based lock had a main spring break. Naturally nothing matched up. I bought a mainspring that had arms the same length as my broken mainspring but the tip that engaged the lock plate was in a different position. I drilled for tip in the new mainspring and have been shooting that rifle for several years now. One of these days I will have to plug the old hole in the lock plate. Don't look at my lock plate and assume that my rifle is an original flint lock converted to percussion.

 

[BruceHH]

You do need the new version of the Jaeger cock that is available from Davis. The new main spring would help also.

 

[flntlokr]

your leather looks extra thick to me. cut a hole in the center to allow the flint to move back more. I have the same lock about 10 years old, no problems.

 

[appalichian hunter]

Thinner leather and a 1/2 in. wide flint as stated the flint and leather looks to large. looks like the flint is set to far forward in the cock

 

[toot]

send it to DIXIE GUN WORKS and they will fit one to it.

 

[Fire-Steel]

Try a thinner flint and leather and adjust for either bevel position for best contact. Top third of the frizzen is the best area for optimum spark.
Its not the amount of sparks, but the placement of the sparks.
These locks usualy spark well. Most of the time the flint thickness makes all the difference.