Replacing an old lock with a new one

[AllenNewberry]

New guy from NW Arkansas here.  I have obtained an old gun that is missing the lock.  I am trying to replace the missing lock with a new one.  I have printed pdf’s from Track of the Wolf and have found that the Davis Tulle de fusil seems to be the closest fit.  However, it’s productions seems to be on hold.  Here is the gun in question:

[rich pierce]

Looks to be a late flint English gun with a round-tailed lock originally.

Fitting a new lock to a mortise is not easy. Will the lock bolts line up? Will the sear be near where it needs to be? Is the width of the bolster appropriate? Can the plate be shaped to fit the inlet? Is the center of the pan to the fence distance going to work?

If large enough, the Chambers gunmaker’s lock may be your best bet. It’s got a large flat rectangular plate.

Are you looking to restore to use or just have it look complete?  I have a round tailed lock that might work.

[AllenNewberry]

Looks to be a late flint English gun with a round-tailed lock originally.

Fitting a new lock to a mortise is not easy. Will the lock bolts line up? Will the sear be near where it needs to be? Is the width of the bolster appropriate? Can the plate be shaped to fit the inlet? Is the center of the pan to the fence distance going to work?

If large enough, the Chambers gunmaker’s lock may be your best bet. It’s got a large flat rectangular plate.

Are you looking to restore to use or just have it look complete?  I have a round tailed lock that might work.

The chambers Siler lock which the gunmakers lock is based on runs into the issue of the bolt hole missing the bolster and hitting the part next to it. (Red circle on the picture) Which I would assume would happen with the gunmakers lock as well.


I am trying to make it look as close to original as I can while making it function. It does seem to make the process more difficult. I also want to do the work myself so that I can learn about these guns.I do plan on using it.  But, I doubt it sees a ton of action.

[AllenNewberry]

Here is what I found with the Davis Fusil de Chase lock. Seems to fit pretty close to the original mortise.  I think I should be able to make it round and still have it fit.  But, the lock plate bolt comes off the edge of the bolster.  (Red circle on photo.)  Some thinking and advise says narrowing the screw a bit may help.  Which makes sense to me.  Granted it would have to be inletted first to see where it actually lands.  And, I would have to find one of the locks. I am open to other locks.  But, I printed all the pdf’s of locks that looked like they might work on track of the wolf and this one seems to be the only one there that would work.

[rich pierce]

It may work. If that’s the main thing, not having it looks like it belongs, I’d see if some steel can be added to that big bolster without interfering with the mainspring and tumbler.

[Bob Roller]

If you have a milling machine or a friend who does that is a minor problem. Locate exactly where the screew will go and start the cut with a light touch and then go down slowly.I would use a 3 flute end mill for this and then after it goes thru,turn the plate over and use the drill that is recommended for the tap.Countersink the hole the depth of one thread to help start the tap.
Bob Roller

[whetrock]

I think your suggestion, Bob, is to mill off the corner, so that it won't interfere with drilling.  In contrast, it seems like Rich's suggestion is to add more metal, so as to make the bolster wider and a bit longer, strengthening it there where the screw needs to go.

I've used Rich's approach before, when repairing a lock where the builder had put the lock screw hole too close to the edge of the bolster and it had broken through the edge. The important thing to keep in mind, as Rich mentioned, is that there has to be room for the top of the main spring when the lock is in cocked position. On some locks, there is plenty of extra room there, but on some others, none at all.

[AllenNewberry]

Good to hear some confirmation on a couple of different options for making it work.  I’m still keeping an eye out for other possible options. But, so far the Davis lock still seems to be the frontrunner by far.  Aside from the fact that I would still have to find one.

[mtlonghunter]

Have you tried caywood locks or the rifle shops.  lots of options besides track.

[AllenNewberry]

Have you tried caywood locks or the rifle shops.  lots of options besides track.

I have looked at their photos and descriptions.  But, they don’t seem to have printable pdfs which allow me to see how well they would likely fit. Several locks look like they would work.  But, some spring is in the wrong spot when my screw would hit it or the shaping is far enough off that I would either have to add metal to the lock or add wood to the stock.  And, I can’t really tell that from a single front view photo on a website. Which does make Track of the Wolf the best spot for shopping them that I have found.  It would be different if I wasn’t trying to fit a preexisting mortise/gun.

[Bigmon]

Larry Zorne has locks similar?  M&G

[Bigmon]

Sure it would be nice to have the bolster big enough to allow the lock bolt.  But if it interferes with the spring, that's no good.
But from the looks of things, Bob's suggestion makes a lot of sense.  Just remove enough bolster for the bolt to pass.  There should be enough thickness for the bolt threads to hold well.  After all, it's enough for the front bolt?
Just my two cents?

[JTR]

  But, they don’t seem to have printable pdfs which allow me to see how well they would likely fit.
[/quote]

Take a picture of the lock from their catolog with your phone. Send the pic to your computer, size it correctly, and print it out.

[rich pierce]

TRS locks assembled cost $400 plus. It’s hard to find a good lock assembler who doesn’t have a big backlog.

[AllenNewberry]

  But, they don’t seem to have printable pdfs which allow me to see how well they would likely fit.

Take a picture of the lock from their catolog with your phone. Send the pic to your computer, size it correctly, and print it out.
[/quote]

That would work if they show both sides of the lock.

[bluenoser]

Camera angle can really distort an image.

[whetrock]

One of the advantages of the Track of the Wolf photos (or they claim, anyway) is that their photo process removes (as much as possible) the parallax, so the photos are supposed to be properly proportioned across the entire image. As Bluenoser points out, that's not so for a regular photo. But you can still resize stuff like JTR suggests and get some idea of what will work, especially since most lock retailers post both the length and height (usually the height right behind the fence). Since a computer image can be adjusted for width and height independently, it's not hard to scale a computer image to approximate measurements. I usually do it with images dropped into a Word document, since that's what I'm gonna print from anyway. I also set the screen display so that the "paper" as it shows on the screen is 8 1/2" (the width of a piece of regular printer paper). (On my laptop the setting for 117% is what I need.) Then I measure the images directly on the screen, using a plastic ruler, so as not to scratch the screen. Sometimes a image may be right on the money on the screen, but off just a tiny bit when I print, but it's not hard to tweak an image a time or two until it prints to exactly the length of the posted measurements.

[AllenNewberry]

One of the advantages of the Track of the Wolf photos (or they claim, anyway) is that their photo process removes (as much as possible) the parallax, so the photos are supposed to be properly proportioned across the entire image. As Bluenoser points out, that's not so for a regular photo. But you can still resize stuff like JTR suggests and get some idea of what will work, especially since most lock retailers post both the length and height (usually the height right behind the fence). Since a computer image can be adjusted for width and height independently, it's not hard to scale a computer image to approximate measurements. I usually do it with images dropped into a Word document, since that's what I'm gonna print from anyway. I also set the screen display so that the "paper" as it shows on the screen is 8 1/2" (the width of a piece of regular printer paper). (On my laptop the setting for 117% is what I need.) Then I measure the images directly on the screen, using a plastic ruler, so as not to scratch the screen. Sometimes a image may be right on the money on the screen, but off just a tiny bit when I print, but it's not hard to tweak an image a time or two until it prints to exactly the length of the posted measurements.

Sounds like some good tips.  Thanks.

[Clark Badgett]

What is the overall length and width of the existing lock mortise?

[AllenNewberry]

What is the overall length and width of the existing lock mortise?

Length 5.125”.   5 1/8”
Width .91”. Close to 29/32”

[AllenNewberry]

Here is a rubbing as well:

[Clint]

If you find a lock that will fit the lock mortice reasonably well, consider putting the lock bolt hole in closer to the barrel and re-drilling the stock. That means modifying the side plate which would be easier than welding on a new lock.CSW