Making a lock for an existing mortise

[rich pierce]

I’m making a percussion lock to fit an existing mortise and wonder what approach restorers usually  use.  I’m restoring a later, severely plain, unsigned, possibly homely original percussion mountain rifle to shooting condition.  As purchased the gun had no breechplug, drum, or lock.  No off the shelf available percussion lock would fit the mortise which is square-tailed and somewhat long. I freshed the rifling, a friend breeched it and fit a drum, and next step is to make the lock that will work.

 I guess there are 2 basic approaches to take:
1) make a lockplate to fit the mortise and then fit the internals and hammer so the cock hits the nipple and the sear is where it needs to be.
2) assemble what is essentially a gunmakers lock on a big rectangular plate and get it lined up, then cut the plate to shape.

I used existing finished internals off a L&R later flintlock I bought here, that was missing a lockplate.  i considered using the Chambers Gunmakers lock but it is flint, maybe a little large, and would need some welding up if I didn’t want to leave the pan remnant, and so decided to fabricate with internals that seemed the right scale for the job, and make the plate out of flat stock.


 #2 but it was challenging to cut out the lockplate to fit the drum, fit the mortise, line up the hammer, and keep  the sear where it needs to be.  If I built more locks and was better at drafting I’d choose option 1 above next time.  I felt it was safer to make it, then position it, then cut it to fit.

How would/do you do it?

[Daryl]

I did this Rich, quite a while ago - maybe 6 or 7 years, don't remember exactly. I was finally attempting to re-barrel my wife's TC Seneca as the original

barrel ringed slightly (1/2 ring) at the rear sight screw. They had drilled the screw almost to the bore & that is where it 'rung'.

I rebarreled the piece, then decided the lock should be replaced. Something inside had broken- can't remember the details as I threw it away. What was

needed, was a rifle lock that had a plate the same size or slightly larger that could be put into the TC stock.

So- I traced and cut out the plate size, then compared it to the locks in Track's book. Surprisingly enough, a Hawken lock plate was slightly larger than the right size,

so I bought the lock & filed it to fit the TC lock mortise, perfectly, and inlet the parts, also easy as they'd really hogged out more than they needed to for their coil spring lock.

To make it look a might better I replaced the Hawken hammer with a Bedford County percussion hammer.  I also shortened and cast a new forend cap for the 36" GM .45 barrel

I put in the stock.

So - tracing what was needed, then comparing to Track's book of full sized locks, made finding a replacement, easy.

 

[M. E. Pering]

If it were me. I would take a picture of the lock mortise, and transfer that to computer.  Then, I would get it to fit actual size when printed out, and print it as a transparency on acetate.  Next, I would take that transparency and compare it to the internal sides of the TOTW catalog, and see if any match, and if so, you have your solution.

However, next best option for me would be to find one as close as possible, and see if it could be adapted to the existing mortise.  The one thing I would not want to do is modify that mortise if at all possible.  But I would say that your chances are pretty good for finding a close match, since most modern reproduction locks are copies of originals.

I have never tried to restore a gun before, but I do have a little background in archaeology, and I imagine the techniques applied in restoration to be similar. 

M. E. Pering

[Hudnut]

I have made patterns by laying a piece of paper over the inlet, then rubbing my thumb around the edges.  This will leave the outline of the inlet.  Cut out the paper to make a pattern for the lockplate.

[Pukka Bundook]

Done exactly the same, Hudnut.

[Daryl]

I have made patterns by laying a piece of paper over the inlet, then rubbing my thumb around the edges.  This will leave the outline of the inlet.  Cut out the paper to make a pattern for the lockplate.

exactly

[Dan Fruth]

You can get thin clear Mylar sheet...I use old xray sheets (.008 thick) for transfer. Secure it over the mortise and trace the outline, then cut the sheet with scissors and fit it to the mortise ( this can be filed to fit).Once it fits properly, draw on the Mylar the location of the parts. You then have a working template for your steel.The hammer you intend to use can be traced and cut from the same material, which can be laid on the lock plate template while in the mortise, and the tumbler shaft hole marked to get proper perspective.....Just my 2cents....Good luck

[rich pierce]

I really like the idea of taking a picture of the mortise, scaling it, taking a picture of available new locks’ internals, and superimposing them to see what works.

I did trace and make a template that fit the mortise perfectly, and compared it to Track’s pictures, but no existing new percussion locks at Track are long enough.  So making a lockplate was essential, then fitting the guts and lining things up. I found the approach to be very different from a new build, and a fun puzzle as it’s necessary for the hammer to strike the nipple, the sear to be in the right position (seems to be the most critical dimension for this sort of project), the plate to fit the mortise,  the bolster to line up with the existing lockbolt hole, and all the internals to fit within the existing mortise (mainspring not fall below the inlet, top lobes of bridle not intrude above the inlet, etc.). Luckily things look like they are working out. I’m waiting on a percussion hammer to arrive from Track and then I should be good to go.  Pix to follow.  If we weren’t traveling for Thanksgiving, I could maybe finish it this week and be shooting it next weekend.

This will be my “heavy” rifle for bench and cross sticks.  It has one of those big barrels with a tiny hole.  Daryl, not sure you’d like it - it will not kick a bit.  It’s .36 caliber, with a 46” long heavy swamped barrel.  If it turns out to be accurate I will probably the-create the original gun, as the current stock won’t hold up well under sustained use.

There’s one heavy original target gun in our club that has been reborn many times.  There are multiple dovetails on multiple flats as the 1.5” barrel has been freshed and re-breeched, new sights and underlugs made and added, and it has probably been restocked 4 or 5 times. That continuity to the original percussion era, a barrel that has passed through many hands and has probably won matches for 150 years, has a lot of interest for me.

[Bob Roller]

I have made a couple of these reverse engineered locks,one as I recall was
English style plate that was not a top of the line style internally.I made a
card board template from a shoe box and then made the plate and used
one of my Hawken type mechanisms which was what the inlet looked like.
The other one was for a Remington sporting rifle marked L.Devendorf in
Cedarville,Iowa. Nice rifle with silver trim and Remington cast steel barrel.
This was in 1963 before I had any decent shop equipment.I still have that
plate pattern in my collection.
The English lock was about 25 years ago and I remember the owner bitching about
the price which was about $150 for the labor and hammer.I will NOT take on
any more of these jobs now at any price.

Bob Roller

[Curtis]

Rich - I have done this once for a restoration project, making a percussion lock to replace a flintlock that had been put on a gun to make it appear older than it was.  The flintlock did not fit the mortise well.

As several have mentioned here, I made a pattern of the lock mortise and transferred it to a steel plate of the appropriate thickness.  I purchased a used lock of similar size to the new plate and used the internals for the new lock.  to properly locate the parts I positioned the donor hammer where it would function with the newly added drum and nipple and marked the location of the tumbler shaft.  I then positioned the lock plate the replacement parts were taken from so the tumbler shaft hole mated with the one marked on the new lockplate and clamped them together.  Then I used transfer punches through the holes in the donor plate to mark the centers of the new holes, then drilled them to required sizes, and tapped the holes that were for screws.  When assembled and all the parts appeared to line up properly I disassembled everything and braised a bolster to the plate.  Last was filing the plate and bolster to fit the drum.

Hope that makes sense!
Curtis

[jerrywh]

 I like Dan Fruth's idea, about the clear mylar template. 

[rich pierce]

Bob and Curtis, good explanations. I too used an existing lock as a template for drilling and reaming  the holes. Worked great. First time this shadetree mechanic used a reamer. Such a clean and tight fit. And I used Kasenit at the tumbler hole. That’s a winner.

I will say it’s handy that major lock makers (Chambers; L&R; possibly Davis) use similar or identical internals across several lock models. Because I had a L&R lock on hand from 1977 I was able to use that as a template for using internals from s recent L&R flintlock I bought for spare parts or a rainy day.