Some simple lock modifications.

[tallbear]

   I am currently making a reproduction of the long lost Christian Oerter for the Museum of the American Revolution in Philadelphia.Due to budget constraints the reproduction called for " off the shelf parts" rather than making a bench copy and that is what was agreed upon.After thinking about it for a while I decided to make some changes so the lock better represented the original.Jim and Barbie Chambers had graciously donated the lock for the project so rather than a stock Siler lock originally planned I had the send me one of their Gunmakers locks.My new plan was to not only duplicate the overall shape but also unbridle the frizzen.Once I completed that I notice that  on the original lock the lock internal screws were blind.Seeing the screws really bugged me so I made them blind.Normally I would just take the plate to a friend and have him weld up the holes.This time I tried something different which was pretty easy and yielded pretty good results.I though I would share here ,it might help someone in the future.

Here is the original lock and one of Chambers Gunmakers locks for comparison.




My basic process was to slightly cone the outside of the screw hole.Slightly score the cone with a square graver.Then run an 8-32 screw a turn or 2 in the hole cut it off proud and peen it into the hole.I scored it with a graver so the screw could not ever back out.In this photo you can see the pan screw has been filled and filed flush.



In this photo you can see I unbridled the frizzen.Since the 8-32 frizzen screw comes from the back I need to fill the area where the screw head recess was.I made a plug and silver soldered it into place.Using a carbide chucking reamer I reamed the frizzen to accept a 10-32 screw.Then I drilled and tapped the hole in the plate for a 10-32 frizzen screw from the front and cut and filed the bridal off.



In this photo you can see I filled the sear spring screw and the sear screw using the same process as I did with the pan screw.A little tip when peening the screw on the front run another screw in from the back so you don't strip the threads while hammering on the plug.



I still have a little shaping and cleanup left to do but I think my modifications have made a closer style lock for the gun.



Hope this opens up some possibilities for others.

Mitch

[Robert Wolfe]

Nice! Hope this ends up in Tutorials.

[ed lundquist]

It sure looks more better, good tips, thanks!

[Tim Crosby]

 Good thinking and nice job Mitch, got any other plans for it?

   Tim

[wpalongrifle]

Nice job Mitch!!!!

[smart dog]

Hi Mitch,
Way to go!  This kind of stuff stuff really floats my boat.

dave

[B.Barker]

Looking good Mitch.

[duca]

Awesome! keep the pictures coming.

Anthony

[Daryl]

Oh yeah - totally awesome.

[Curtis]

Nicely done!  I would say you reached your goal of inspiring others!!

Curtis

[smallpatch]

Very nice Mitch. Most people woul have just used a Siler, and moved on.  That kind of thing is what separates the stockers from the builders.
Way to go!

[ScottH]

Agreed, nice work!
I would be interested in how you developed the lock plate shape. Did you draw it freehand? Use a good photo to get the shape so close?
Thanks!

[J. Talbert]

Great job so far... any plans for the frizzen spring?

Jeff

[elkhorne]

Mitch,
Thanks for the tutorial on how you used the Chambers Gunmakers lock to customize for your Oerter rifle. You open the door for many of us who either have a lock to replace or want to make something a little closer looking to an original. I attest to how you filled the screw holes to make them blind. I did that same technique on a mis-drilled hole in a side plate and after completion, you can not even see where it was. Thanks and look forward to your build photos.
elkhorne

[Ed Wenger]

Looks great, Mitch!  Thanks for posting.  Best,

       Ed

[tallbear]

Thanks everyone!!!

In other circumstances I would still weld up the holes but this is a viable option .I don;t think I will do much more to the lock other than a little reshaping of the cock and the pan.I've spent a lot of time modifying the buttplate and trigger guard as well and need to get on with building the gun.

Scott H
I developed the pattern by first taking a straight on photo if I can.It's difficult to use a photo from books as the are often taken from an angle to maximize the light so they can be missleading.Then I resize the photo the computer.This gets me the basic shape.I also had a full set of measurements for this lock which allowed me to better define the copy. Once I get it roughly to shape I do the rest by eye .I also should mention often an exact copy is'nt possible due to the lock internals being different.That is why "by eye" sometimes is the best solution........

Mitch

[BOB HILL]

Mitch, thanks for sharing this information with us. Look forward to following this project.
Bob

[t.caster]

Nice job! You must have plugged the frizzen screw hole and re-drilled & tapped that too.

[Scota4570]

When making the bridle holes blind, do you tap a blind hole?  Seems that would leave only a couple of threads?   Or, do you insert a couple of studs and make the bridle flat? 

[tallbear]

Nice job! You must have plugged the frizzen screw hole and re-drilled & tapped that too.

Hi Tom
Yes I plug the whole and then use a larger screw (10-32) for extra strenth over the existing 8-32 screw that was used with the bridle.

When making the bridle holes blind, do you tap a blind hole?  Seems that would leave only a couple of threads?   Or, do you insert a couple of studs and make the bridle flat?

Scota4570

Yes it's a blind hole which means I slightly shorten the existing screws.Most 18th Century Quality locks were done this way particularly European made.I don't foresee a problem.

Mitch

[Marcruger]

I always read your posts Mitch, and I am never disappointed.   Lovely lock work.  You definitely have the eye for lines as well as detail.  God Bless,   Marc