Thanks again Gus. Sadly the fit between the tumbler and lock plate has more movement than would seem fit, which is somewhat surprising as this was one area where I was (or thought I was) quite careful not to over polish. I’m picking up about .004 for the most part but confess that the axle of the tumbler also isn’t perfectly round so that at one spot towards the top of the tumbler the gap would be more like .007-.008 .......
But holding the spring up to a square it does actually look reasonably square so your observation about the sloppy tumbler causing the problem is more likely the case than my thought of the spring being off square. It really is a bit of a mess and I can’t now think how to remove that sloppiness, other than if I can find someone who could perhaps machine it down further and press a sleeve onto it....
In fact of everything that I’ve done with this lock the tumbler really is the bit that I feel that I have cocked up the most so it makes sense that it would be the cause of the issue.
I have already tried to contact TRS again to buy a replacement tumbler due to my initial cockeyed cock-screw pilot hole drilling efforts. I’m also short a 6-32 UNC screw that was missing from the kit and which seems to be impossible to source here in Australia. But with no responses from TRS I’m floundering in the breeze unfortunately and trying to recover what I have... (I really can’t think of anything that I may have said or done to upset TRS but they do seem to have me on ignore, I’m hoping they may respond to a letter).
Tooling wise I have nothing with the sort of precision that I really need to put something like this together - files, a Dremmel, a large pedestal drill with a basic Chinese two way vice, a couple of large belt sanders and some grinders and polishing wheels and a couple of sets of Verniers. As far as metal working skills go I’m a capable blacksmith and welder but I am really not skilled or experienced with fine work like this with metal.
So don’t worry about being critical of my work with this lock - I’m far more critical of myself and was well aware before hand that I’d struggle with this level of fine work with the tools that I have and my skill level to work to fine tolerances - hence initially ordering the pre-built lock....
Ideally I wonder if I could find someone here in Australia who is experienced and skilled with flintlock builds to see if they could possibly recover my mistakes before I make more of a mess of it.
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I had a lot of trouble drilling the tumbler hole on my 1803 lock, part of the problem was the hardness of the tumbler.
I thought I had annealed the tumbler and was getting a lot of chips from the drilling operation, stopped the result was I had to up the screw hole from 6/32 to 8/32.
So, in nut shell, 4140 steel needs to be annealed at 1500 degrees for about 45 min to 1 hour and air cooled. 4140 steel that is too hard is a pain to work with, as it workhardens, this is why 4140 steel is often used in sledge hammers and gym weights / dumbbells.
I drilled my lockplate tumbler hole with an undersized drill and filed it open very slowly with a need file so I had a nice rotation, the arbor itself I polished with a diamond file and made sure I got a good rotation. When I was completed the lock I made sure all parts were hardened and then tempered at 580-660 for 1 hour so the steel was too hard but tough enough to work and not crack.
My lock Didn’t have a fly. This of course is more complicated as a fly and sear must integrate well in the action, if that fly is dragging on the sear slightly it could jam up the action. Most sear’s have a fly trail of some sort carved into the it to avoid this, but I don’t see that on the baker Sear, which makes me wonder if the lock would work better without it.