Lock work

[Acer Saccharum]

I worked on this lock a lot. I must say, right out of the box, it was a good sparker. This is a Davis Colonial. A massive brute of a lock.

There were some things I wanted to change, and with one thing leading to another, I did a lot of tweaking all told.

Cosmetic:
Top jawscrew: I changed the profile from the full round ball to a more flattened profile.
Lock Tail: I filed a panel and groove across the tail to make it more like the original I was inspired by.
Cock retaining screw: I turned a new on at 5/8" dia head, again, more like original aforementioned.

Mechanical:
Cock jaws:The jaws would not hold a flint for very long. So I filed the plane of the top jaw so that the collar on the screw bore on the outermost edge of the hole. In other words, I filed the jaw down on the side where it bears against the cock upright. Now it holds flint like a champ.
Frizzen: I annealed it to polish it (much easier than polishing a hardened frizzen). While it was annealed, I used a torch to bend more curve in it, to get more of a shearing action.
Frizzen spring: the frizzen was bouncing back hard enough to bust my flints. So I opened up the spring with heat and rehardened and tempered it.
Fly: I noticed the fly was holding up the downstroke (when I had the mainspring out). I ground and polished it down until the sear floated over the halfcock notch without binding.
Casehardening: Once everything was re-shaped and adjusted the way I wanted it, I casehardened all the parts that needed it. Plate, screws, Cock and jaw, frizzen and bridle. On my forge with charcoal.
Triiger creep: a simple stoning of the sear notch and sear tip fixed this. Nice, crisp let-off. About 4 lb pull.

This lock is now incredibly fast, which is a testament to Davis' mighty mainspring. I am using a Rich Pierce White Fire flint, which mills off burning hunks of steel. There are actually metal cinders in the pan when I dry fire!


I write this because this is the first time I really understood what I had to do to get this lock working form 'OK' into 'Fabulous'. Every lock I buy has needed some tweaking to get it to my satisfaction, and I feel like I really 'got it' on this lock.

As I understand, most casehardened locks got polished bright from this Colonial time period, before color case was generally used as a decorative treatment, but I like the looks of this lock dark. Kind of ominous.

Thanks, Tom

[heinz]

Excellent post, thanks for the information.  Case hardening colors are admirable.

[Acer Saccharum]

PArt of my setup. I use a steel pipe with bottom welded shut. Pack the parts with powdered charcoal, or the ready made charcoal from Brownell's, into the crucible. Lid is turned to fit with little chance for air to get in.



Dumping the parts into water. Note all the safety equip, shield, gloves, etc. This picture is from last year or the year before. But I used the same set-up. I used charcoal briquettes for the fire. It seems to take forever to get a full fire going, but once it's lit completely, you don't need too add any air. It just cooks all by itself. The crucible should be a nice cherry red/orange  for about an hour. Dump the whole load into the bucket. I have a screen at the bottom, otherwise my parts would just melt right thru the bottom of the bucket.

I wasn't going for color, but hardness. But I like the colors I got.

By the way, the lockplate is about .02 longer than it was before hardening. Knowing this, you might want to harden your locks before you inlet them, if you were doing any really fine or critical work.

[Ed Wenger]

Tom

     Great work, really nice looking lock!  I love those Davis locks but as you say, they are brutes.  You got some really nice color there, and I especially like what you did with the frizzen.  Thanks for the info!

                               Ed

[Tom Currie]

I like the dark color also and the larger cock screw.

I also tuned up a tumbler and fly on a recently purchased lock due to the sear hanging up on the fly. A satisfying task once it's done and working smooth.

[Jim Filipski]

Yeah , Yeah. Yeah ...all very nice but show them how to  make a fine pie crust!
Just had to bust ya!
Lock & crusts are superb....I'm sure you heat them differently However

[M Tornichio]

This is a great post. I like the results that were achieved. Any chance we can see the rest of the gun?
Marc

[B Shipman]

The welders mask is a good idea. Iv'e scorched a few eyebrows when that hot charcoal hits the water. I want to see the rest of the gun too.

[davec2]

Tom,

I have case hardened two lock plates lately that warped badly even though I had blocked them with thick steel bars and stand offs.  I had to anneal and re-harden both of them over again a couple of times to get them straight AND hard.  Did you block this lock plate in any way?

[A.Merrill]

    You always come up with something nice. Good job.    AL

[Michael]

Tom,

Nice looking lock!  If I am using a lock that does not have set triggers I usually don't put the fly back in, it really serves no purpose. I'm getting quite a collection!

Michael

[Don Getz]

Tom.........just purchased one of those locks for my next build.    Seems to be a rather "robust" lock.   When I saw the
amount of changes you did, I was wondering if you thinned up the cock, I am referring to the lower, flat portion.   It must
be at least a 1/4" thick.....just seemed massive to me..............Don

[Acer Saccharum]

Thanks for the kind words, gentlemen. I will post pics of the gun in another post, as soon as I can get around to photo-ing. I have been very busy with work-work, so the gun-work has taken a bit of a back burner.

I credit Dan Phariss for making me think about curving the frizzen more. With the flint bevel up, the flint arcs into the frizzen, making a steadily increasing shearing cut, instead of impact and a scrape.

Dave Kanger got me thinking about flint position, why my frizzen bounces back. If I mount the flint bevel down, it makes the impact higher up on the frizzen. The mainspring is so !@*%&@ strong, it will throw the frizzen forward hard enough to bounce back. Originally, the frizzen would bounce back no matter what flint position I had, now it's just when I have the flint bevel down, and extended out from the jaws. This happens evean after I spread the frizzen spring a lot, which increased the holding pressure. So flint position is very important if you are having lock issues.

Bevel up, the sparks go right in the center of the pan. Bevel down, they go 3/8 ahead of the pan.

Tom

[Acer Saccharum]

Don, it is a massive lock. A brute. I did not thin the cock, tho' I did think of it. It would have meant hours of filing, which convinced me to go more 'stock lock'.

Like I said earlier, this lock works right out of the box. Most of the changes were made for fine tuning.

Thinking back, I used this lock as-is at the range several times, bevel down, then noticed that my flints were disappearing at my third or fourth time out shooting. Like, 3/16 of the flint gone after one shot.

I think the impact of the frizzen on the friz spring may have been bending the friz spring permanently, a little more at each shot. This weakening of the pressure of the frizz spring allowed the frizzen to bounce harder at every shot, until the lock was auto-knapping off the end of the flint at each shot.

Tom

[Jim Kibler]

Looks as though the lock turned out well.  I've looked at this lock and had similar thought to those mentioning how massive it is.  I realize RE Davis shows an original lock that was the inspiration for their design, but I question how typical a lock such as this was.  Can anyone point out an existing longrifle with a Germanic lock of proportions approaching this lock?  I've not looked with this intent, but when I think about it nothing comes to mind.  Not even the early Moravian or Reading stuff.  This is not to say the lock doesn't look cool or that I might not use one at some point. 

[rich pierce]

I don't recall a Germanic lock that massive looking on an American longrifle (it's not overly large, just stout everywhere) but the Griffon rifle has a pretty stout lock on it of different styling.



Tom and I chose this lock for making bench copies (he's done, I've not started) of an original, unattributed Revolutionary War period rifle of unknown regional origin.  This Davis lock is about the same length and width as the original but is stouter all over.

C'mon, Tom, show the original lock again.

[Acer Saccharum]

View of original lock. Note this one is screwless, no sear or bridle screws showing, Frizzen is bridled with screw from INSIDE the lock. The Davis is bigger, both in height and length, but the Germanic flavor is good. The Siler is too delicate. Rather than make a lock, I chose to use the Davis. I also think rather than get hung up on getting the lock to look exactly like the original, I think like the builder would have used the Davis lock on the next gun if he couldn't get the original style.

Note the perfect condition of the screw heads, the separate pan, wonderful fitting of parts, beautiful filing on the frizzen spring. This was not a cheapo lock.

The condition argues in favor of casehardening your locks.

[Dphariss]

I really like the lock colors, excellent work all around. Reworking a lock and having it come out better, faster etc is really fun. I need to get a real forge and try charcoal hardening. But I have friend who is an expert at charcoal hardening so  

Back in the June 1966 Muzzle Blasts there is an article by Mark B. Burnham,  Home Gunsmith "Adjusting a Flintlock". In which he made a "try lock" that could be adjusted for  frizzen and mainspring tension, frizzen angle, frizzen spring location. He used a frizzen with a 2" radius curve.
This was very informative to a budding FL shooter and maker. Experience has shown that the curved frizzen and the frizzen spring tension comments are correct. I think he is in error in some things BUT one must remember that when buying a lock or lock casting some things are already set in stone. Thus his comments on cock jaw angle have proven to be inaccurate in my lock tuning experience. Since other things are impossible or very difficult to change, the changing of the bottom jaw angle can solve many problems. It does about the same thing as putting the flint in upside down in some cases  (Burnham's drawing has it bevel up I find in looking up the magazine this AM )
As an excerise those with the interest:
Go to the TOW site and look at the photo of the large Siler this is a very good lock and seldom needs any "help", maybe a stiffened spring at most. Imagine where the cutting edge of the flint will be, where does it point, with the cock down. Now do the same with the other locks pictured. Where does the flint point?  Many others are "worrisome" to my eye. Also look at the frizzen angles and curves.

I was 16 when I read "adjusting" and I learned a lot and experience has born out that Mr Burnham was right in some key areas and I think wrong in others.  But I seldom agree with anyone on everything

Dan

[Jim Kibler]

Tom,

That is a wonderful lock you just posted.  Seems you had posted it before, but I had forgotten about it.  Do you have any background information on it.  Is it from an existing gun?  Any markings on the lock?  How long is the plate?

Thanks,
Jim

[Dphariss]

The original lock is definitely not a cheap export lock.
It appears to be first quality with all the little things done that make it a pleasure to look at.

Dan

[Acer Saccharum]

But I seldom agree with anyone on everything

Dan

Really? I hadn't noticed. 

Thanks for your input on the flint position and curvature of the frizzen. I will look at all my new builds with a different eye.

Tom

[Acer Saccharum]

Tom,

That is a wonderful lock you just posted.  Seems you had posted it before, but I had forgotten about it.  Do you have any background information on it.  Is it from an existing gun?  Any markings on the lock?  How long is the plate?

Thanks,
Jim

Jim, for the first time in memory, you have more questions than answers. 

The lock is owned by a friend of mine, installed in its original rifle, which he will not let out of his sight. He let me copy his rifle, make drawings, photgraph, and I could do anything I liked with it, except take it out of his house. He might be willing to let me take moulds off the lock some day. I forget what the length is, but it's about 3/8" shorter than the Davis Colonial, so that would make it about 5 1/2 x 1" tall.

[chris laubach]

Looks as though the lock turned out well.  I've looked at this lock and had similar thought to those mentioning how massive it is.  I realize RE Davis shows an original lock that was the inspiration for their design, but I question how typical a lock such as this was.  Can anyone point out an existing longrifle with a Germanic lock of proportions approaching this lock?  I've not looked with this intent, but when I think about it nothing comes to mind.  Not even the early Moravian or Reading stuff.  This is not to say the lock doesn't look cool or that I might not use one at some point.  

I agree! I have looked at quite a few locks, German, English, late and early and I have not come across a lock that is as massive as this one. I was told that the lock that was the inspiration for this lock was a pistol lock?
I bought one of these locks to use but found it to be to much work to bring it down to size. WAY TO MASSIVE.

Tom,
I think you did a great job with the lock


Chris Laubach

[Acer Saccharum]

This lock is not for the faint of heart. 

[JCKelly]

Mark Burnam . . . name brings back memories. About 1955 Dad bought me a .535" brass ball mould from Burnam, for use in my H. Aston horse pistol, dated 1847. Never could hit anything with it but liked the BOOM.

Have you considered damaging those beautiful case colors locally, enough to temper the frizzen neck so it does not snap off one fine day? Given that it sparks so well it probably really is not file-hard, as one would expect of water-quenched 1095. Still, as-hardened frizzens have been known to snap at the neck, unless locally tempered.