Resurrecting an old Back Action Lock...

[John C IND]

The above photos are the requested ones of the Burson trigger group.
The triggers are mysteriously clean for an alleged 'closet find' original rifle..., The lock was much dirtier and rustier.

[Bob Roller]

I saw the word "Tumico"on the steel ruler and I have
a George Sheer vernier caliper with that marking and
a 0-1" micrometer so marked. The "Tumico" name
stands for Tubular Micrometer Company and they were
located in St.Cloud,Minnesota.The vernier is a work of art
and I used it a lot during a job at a Babbitt bearing shop in the late 1980's.
Mr.Sheer owned the company and supplied micrometers to tubing
makers.
The triggers from that old rifle look good and I wish you well on the restoration
of the lock. The next time you make a tumbler,get a piece of 1144.It machines as easy as
12L14 and oil hardens like drill rod (01).
Bob roller

[Captchee]

 i would agree with Bob , nice trigger .
 the ones i have seen didnt have a hammer head type profile to the front trigger . instead it was shaped more like a  joint on a bone .
 big thick main spring as well

[Dennis Glazener]

 John, you can post all the links in one post just do a new line after each one and they will all display in a single post.
Dennis

[Hungry Horse]

 The original tumbler looks like it may have suffered many old repairs over the course of time. You seem to have a very good start on the new one, which should perform well. The lock seems to be marked Ashmore, which is a fairly common trade lock. You might find a tumbler for this lock if you turn over the right rock.  I agree with the other that the triggers are very nice.

                               Hungry Horse

[westbj2]

Here is a simple solution to the no-half cock tumbler.  Over the years I have run across 3 original percussion guns with this device still hanging on the trigger guard.  The peg rests under the throat of the hammer and keeps it off the cap, when the lock is cocked the peg falls away.
Jim

[John C IND]

Interesting idea of the peg to block the hammer, that may be the way to go if I can't make a half cock notch work, and just replace the tumbler like it was found (without the break)
I plan to drill the old one and silver an allen head bolt to the end of the break, so I can see if the notch is in the proper place... It would be a shame to put all the work into duplicating the piece only to find the part was a poorly fitted replacement. No real way that I know of to observe the interaction of the sear and trigger without rotating the tumbler under load.

[WVlongrifleman]

Interesting idea of the peg to block the hammer, that may be the way to go if I can't make a half cock notch work, and just replace the tumbler like it was found (without the break)
I plan to drill the old one and silver an allen head bolt to the end of the break, so I can see if the notch is in the proper place... It would be a shame to put all the work into duplicating the piece only to find the part was a poorly fitted replacement. No real way that I know of to observe the interaction of the sear and trigger without rotating the tumbler under load.

I have probably 40-50 back action locks for parts/restore, a lot of them have decent tumblers. If you end up needing a tumbler let me know exactly what your looking for and I'll see if I can dig one up for you.

[John C IND]

WVLongrifleman, Thanks for the offer.  There is a clear photo of the old tumbler above, and the lock is an N. ASHMORE.
If you'd have a donor lock or a similar tumbler, I'd be interested.  A hammer fitted would be a plus.

[westbj2]

Looking at the old tumbler and your sketch, I could well be that you are dealing with a tumbler that has been replaced at some time in the past.
In an ideal world with the correct geometry in the lock internals, you should be able to put a square on the center of the sear pivot and the center of the tumbler axle and find that the line coming down from the tumbler intersects and is parallel with the bearing face of the full cock notch.  The sear is then fitted to this relationship.
Jim

[WVlongrifleman]

WVLongrifleman, Thanks for the offer.  There is a clear photo of the old tumbler above, and the lock is an N. ASHMORE.
If you'd have a donor lock or a similar tumbler, I'd be interested.  A hammer fitted would be a plus.

I meant one with half cock (I would need measurements), but I could probably turn up one like you have pictured. As far as lock plates I don't think I have one just like that

I agree that it looks like a make do part, hard to tell if its original to that lock or not

[John C IND]

Here is the partially assembled lock. The plate and bridle holes measure .339 and .166 diameters respectively.
The tumbler itself measures .329 and .162 diameters.  The root of the full cock notch measures .388 from pivot center and the full cock lip/tip as it were is .440 from pivot center. The body is .206 thick. The assembly is quite sloppy as in the pivots sort of 'clatter'.  westbj2, the notch and sear tip fails your square test from the get-go.