I need help with a TRS Baker Rifle flintlock build

[FlinterNick]

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.

 

[Larks]

Thanks again Gus, that’s a really interesting piece of equipment - something that you’d expect to see in a “what is this” challenge. And thank you again for the great advice, I’m going to head into town later in the week to see if I can find a machinist to true the arbour and shim it but in the mean time I will certainly contact Track of the Wolf to see what they can do. I’m still hoping that TRS may respond to my letter.

 

[Larks]

Hi Larks,
I've built and reworked many locks and Gus' advice is bang on. One critical thing to add is you must make sure the inside of the lock plate is flat. With TRS lock sets, that is usually the very first task before doing any other fitting. Take a wide mill or bastard file and carefully flatten and true up the plate.

dave

and there I must make my next confession Dave, the TRS notes on their web site did warn to flatten the lock plate but your post reminds me that I forgotten to do that. Easy enough for me to go back and do, the only shame being that I’m quite chuffed with the heat bluing that I’d managed to achieve after case hardening it - more luck than good management I think though I’m sure that I’ll be able to do it again.

 

[Larks]

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.

I was thinking that my mistake with the tumbler cock screw hole was how poorly I squared it to my drill press but you now have me thinking that it may well have work hardened as I drilled it, amplifying a small alignment problem and skewing the drill bit as I drilled. Once I tapped and plugged the hole with an oversized machine screw I had no real problem getting a straight pilot hole through that for the cock screw.

 

[FlinterNick]

I was thinking that my mistake with the tumbler cock screw hole was how poorly I squared it to my drill press but you now have me thinking that it may well have work hardened as I drilled it, amplifying a small alignment problem and skewing the drill bit as I drilled. Once I tapped and plugged the hole with an oversized machine screw I had no real problem getting a straight pilot hole through that for the cock screw.

Not sure why Rifle Shoppe uses 4140 steel on their locks, 8620 works much better for lockplates and internals, especially with springs made of 6150 steel. It may be because that’s all their foundry will pour, which I can understand. I had the chance to work on a lock kit by Jim Chambers and the process was much easier Mostly because of the annealed 8620 steel.

 

[Artificer]

Thankyou for that - the fly can only go in the one way so it’s definitely in the right way, however it came as cast with the sprue still attached so I do wonder if I may have over filed it in cleaning it up ..... or not filed it enough...? It is loose in its position but should the edges perhaps be sharper?

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Hi Larks,

I'm VERY glad Dave Person chimed in earlier and I hope he checks me on this and future posts and adds/corrects as needed.

Before going further, here is a pic you posted that has me a bit concerned:

This is a great pic as it shows you need to attend to the angle of the full cock notch a bit. The angle of the full cock needs to be perpendicular to the center of the tumbler arbor. Though the below illustration is a slightly different tumbler, it explains some things for us. See Fig. 2 below for the correct way to do it.

What you have now is the same as "line A" in Figure 2.1. The problem with this is the forward angle much too easily allows the Sear Nose to disengage when you want it to stay at Full Cock. So it is dangerous. "line B" of Figure 2.1 shows the angle going to the Rear. The problem with this is as you pull the trigger, you are actually causing the Cock to go further to the rear as you pull the trigger so it gets heavier and heavier before it finally releases. YUCK!! BTW, if you can't get the full cock notch perfectly perpendicular to the center of the tumbler arbor as in Fig. 2.1, a VERY slight angle to the rear as in "line B" of Figure 2.1 is much, MUCH better than the notch angling forward any at all.

OK, the next post I want to address the Fly more fully, but will get this posted before I lose it or mess it up.

Gus

 

[Artificer]

Hi Larks,

I'm VERY glad Dave Person chimed in earlier and I hope he checks me on this and future posts and adds/corrects as needed.

Before going further, here is a pic you posted that has me a bit concerned:

View attachment 91210

This is a great pic as it shows you need to attend to the angle of the full cock notch a bit. The angle of the full cock needs to be perpendicular to the center of the tumbler arbor. Though the below illustration is a slightly different tumbler, it explains some things for us. See Fig. 2 below for the correct way to do it.

View attachment 91212

What you have now is the same as "line A" in Figure 2.1. The problem with this is the forward angle much too easily allows the Sear Nose to disengage when you want it to stay at Full Cock. So it is dangerous. "line B" of Figure 2.1 shows the angle going to the Rear. The problem with this is as you pull the trigger, you are actually causing the Cock to go further to the rear as you pull the trigger so it gets heavier and heavier before it finally releases. YUCK!! BTW, if you can't get the full cock notch perfectly perpendicular to the center of the tumbler arbor as in Fig. 2.1, a VERY slight angle to the rear as in "line B" of Figure 2.1 is much, MUCH better than the notch angling forward any at all.

OK, the next post I want to address the Fly more fully, but will get this posted before I lose it or mess it up.

Gus

OK, now on to the Fly. The following pic you posted earlier gives me pause a bit.

I'm not sure if the Fly is actually interfering with allowing the Sear Nose to properly go fully into the half cock, should it slip off the full cock notch. Since your full cock notch shown in my post immediately above this cock already can allow this, it is even more of a concern.

Could you take a pic similar to the one in my last post immediately above, that shows a bare Tumbler with no fly in it, but now add the fly and move it as far forward as it will go in the cut out portion of the Tumbler? This may or even should show if you actually need more attention to the Fly. I want to see whether or not the Fly is not allowing the Sear Nose full access to the Half Cock notch.

Gus

 

[Larks]

Those half cock and full cock notches on the tumbler and the toe of the sear were perhaps the two (three) areas that I was most careful with not to mess with their alignment and shape and I mostly just gave them a polish with a scotch bright wheel on the Dremel. The edges of the tumbler had a number of “lips” and dags that needed filing off and one was covering one edge of the full cock slot, you can probably see where I filed that off on the right of the full cock slot here:

I do have files fine enough to take the slot back to alignment with the centre of the pin so I can readily do that.


With the springs off it is much easier to get some better photos showing how the sear sits into those slots:

It does have difficulty finding half cock but here’s how it sits when it does find it (you can also see the outrageous effects of my file on the bridle/tumbler hole and one screw that I impatiently used the wrong size driver head on....one thing that I do have is a good gunsmith screwdriver set for my other firearms )

at full cock:

and against the fly - should the fly be able to hold the sear? It does at the moment....just

and with the sear removed - the large bright scratch on the lock plate was initially caused by a remaining dag on that corner of tumbler but it now persists as another result of the sloppiness of the tumbler arbour:

 

[Larks]

And with the fly removed: NB: To add to my complications, I do know that I need to work on my sear spring as well as I’m not getting a good sharp return on the sear as the cock comes back. I’ve hardened and tempered it twice using the method that TRS describe in their website notes but, being such a small spring, the heat isn’t quite as controllable as it is on the larger spring so I’m not sure if the issue is the spring ability or the length/position of the spring against the sear. It appears to fit well against the sear and it did improve slightly with the second harden/temper cycle so my plan is to have another go at that before anything else.

 

[Artificer]

And with the fly removed: NB: To add to my complications, I do know that I need to work on my sear spring as well as I’m not getting a good sharp return on the sear as the cock comes back. I’ve hardened and tempered it twice using the method that TRS describe in their website notes but, being such a small spring, the heat isn’t quite as controllable as it is on the larger spring so I’m not sure if the issue is the spring ability or the length/position of the spring against the sear. It appears to fit well against the sear and it did improve slightly with the second harden/temper cycle so my plan is to have another go at that before anything else.

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Larks,

Those are GREAT pics! Thank you.

I have to study them for a while before I post further, so hang on for more coming.

Gus

 

[Larks]

Larks,

Those are GREAT pics! Thank you.

I have to study them for a while before I post further, so hang on for more coming.

Gus

Thanks Gus - I’m looking at those photos myself and wondering if I could plug the bridle hole with a screw tapped into it and re-drill it. Or I could spot weld it, file it flush and re-drill it but there’s a risk of distorting the bridle.... Neither would resolve the flat spot on the small arbour/axle of the tumbler but with the ability to drill a smaller hole I could probably file the arbour down very slightly to round by slotting the larger arbour into my pedestal drill.....

 

[Artificer]

Those half cock and full cock notches on the tumbler and the toe of the sear were perhaps the two (three) areas that I was most careful with not to mess with their alignment and shape and I mostly just gave them a polish with a scotch bright wheel on the Dremel. The edges of the tumbler had a number of “lips” and dags that needed filing off and one was covering one edge of the full cock slot, you can probably see where I filed that off on the right of the full cock slot here:

View attachment 91227

I do have files fine enough to take the slot back to alignment with the centre of the pin so I can readily do that.


With the springs off it is much easier to get some better photos showing how the sear sits into those slots:

It does have difficulty finding half cock but here’s how it sits when it does find it (you can also see the outrageous effects of my file on the bridle/tumbler hole and one screw that I impatiently used the wrong size driver head on....one thing that I do have is a good gunsmith screwdriver set for my other firearms )

View attachment 91228

at full cock:

View attachment 91229


and against the fly - should the fly be able to hold the sear? It does at the moment....just

View attachment 91230


and with the sear removed - the large bright scratch on the lock plate was initially caused by a remaining dag on that corner of tumbler but it now persists as another result of the sloppiness of the tumbler arbour:

View attachment 91231

View attachment 91232

You asked, " and against the fly - should the fly be able to hold the sear? It does at the moment....just "

No, the fly should NOT be able to hold the Nose of the Sear, this is GOING to cause damage to the Sear Nose, if not cause it to break off in use.

The reason for a Fly in a lock is because with a fast strike of a spring loaded lever hits the Sear Leg, it raises it enough to disengage it from the full cock notch. However, the pressure is not kept on the tail of the Sear holding the nose away from hitting the Half Cock. So the Fly is there to help the Sear nose skip past where it would hit the Half Cock, because the Sear nose is not continued to be kept out of the way as would be the case when one manually pulls the trigger.

I hope that explanation is a bit clearer than mud.

However, if/when the Sear Nose should fall out of engagement from say a good bump to the firearm, the Fly is ALSO supposed to NOT stop the Sear Nose from falling into the Half Cock and keeping the firearm from unintended discharge. (This can happen easier when the full cock notch is angled forward as in the case of your lock.) The fly as it is in your lock, doesn't allow the Sear Nose to fully engage the Half Cock, so you won't get the fullest amount of the benefit of this Safety Feature in the lock.

However, the Half Cock Notch in your Tumbler is so far forward, I'm not sure if the Fly can be corrected enough to allow the Sear Nose to fully engage.

What I would do before anything else is blacken the top of the fly with a magic marker or blacken it with candle black. Then make sure the fly is all the way forward and use a dull point to mark through the black to show how much the Fly would have to be either thinned or how much more the notch in the Tumbler would have to be cut forward to keep the Fly in a wider and thus more solid/stronger configuration.

Even as I read this, I hope it can be understood.

Someone suggested if you aren't going to use a single or double set trigger, you don't need the Fly in the Tumbler and that MAY be the easiest correction, if you are willing to do that.

If you want to keep the Fly in the Tumbler, I think the best thing to do would be to open the notch forward in the Tumbler for the Fly. HOWEVER, I am not positive about this, so I hope Dave Person and others may chime in.

Gus

 

[Artificer]

Thanks Gus - I’m looking at those photos myself and wondering if I could plug the bridle hole with a screw tapped into it and re-drill it. Or I could spot weld it, file it flush and re-drill it but there’s a risk of distorting the bridle.... Neither would resolve the flat spot on the small arbour/axle of the tumbler but with the ability to drill a smaller hole I could probably file the arbour down very slightly to round by slotting the larger arbour into my pedestal drill.....

I'm not sure how out of round is the Arbor that goes through the Bridle? If you are not dealing with say more than 20-25 percent of the circumference being out of round, I'm not sure I would do anything more than filling in the hole with a screw as you mentioned (I suspect welding it would warp it too much, but I'm not absolutely certain about that because I'm not a welder.) I would then drill it for the Arbor as is.

However, if the Arbor is more out of round than that, you may have enough metal to turn it round on your drill press and then fix the Bridle and drill it for the smaller hole.

Gus

 

[Larks]

Th

You asked, " and against the fly - should the fly be able to hold the sear? It does at the moment....just "



No, the fly should NOT be able to hold the Nose of the Sear, this is GOING to cause damage to the Sear Nose, if not cause it to break off in use.

The reason for a Fly in a lock is because with a fast strike of a spring loaded lever hits the Sear Leg, it raises it enough to disengage it from the full cock notch. However, the pressure is not kept on the tail of the Sear holding the nose away from hitting the Half Cock. So the Fly is there to help the Sear nose skip past where it would hit the Half Cock, because the Sear nose is not continued to be kept out of the way as would be the case when one manually pulls the trigger.

I hope that explanation is a bit clearer than mud.

However, if/when the Sear Nose should fall out of engagement from say a good bump to the firearm, the Fly is ALSO supposed to NOT stop the Sear Nose from falling into the Half Cock and keeping the firearm from unintended discharge. (This can happen easier when the full cock notch is angled forward as in the case of your lock.) The fly as it is in your lock, doesn't allow the Sear Nose to fully engage the Half Cock, so you won't get the fullest amount of the benefit of this Safety Feature in the lock.

However, the Half Cock Notch in your Tumbler is so far forward, I'm not sure if the Fly can be corrected enough to allow the Sear Nose to fully engage.

What I would do before anything else is blacken the top of the fly with a magic marker or blacken it with candle black. Then make sure the fly is all the way forward and use a dull point to mark through the black to show how much the Fly would have to be either thinned or how much more the notch in the Tumbler would have to be cut forward to keep the Fly in a wider and thus more solid/stronger configuration.

Even as I read this, I hope it can be understood.

Someone suggested if you aren't going to use a single or double set trigger, you don't need the Fly in the Tumbler and that MAY be the easiest correction, if you are willing to do that.

If you want to keep the Fly in the Tumbler, I think the best thing to do would be to open the notch forward in the Tumbler for the Fly. HOWEVER, I am not positive about this, so I hope Dave Person and others may chime in.

Gus

Thanks yet again Gus, that it is all understandable. I’m happy to leave the fly out, given the description of what it is intended for. The rifle will only be shot at a range and am not in the habit of snapping a trigger, preferring to ease it off during follow through, so I don’t feel the need to prevent it from falling into half cock or to protect it from accidental discharge. I get the impression that the fly was introduced for a more “robust" use of the rifle in much more trying circumstances.....

Having said that, I’d like to try and get it to work correctly before I do completely discard the idea of keeping it in.

Looking more closely at the fly notch in the tumbler neither side of it looks sharply formed, the back end being slightly angled and the front end the same but also quite rough, so I am sure they could profit from some gentle attention before I start on the fly itself. I do get the feeling that the fly sits slightly too far out from the tumbler, whether that is because of these edge issues, the arbour on the fly, the fly that it sits in or the outside edges of the fly needing attention I'm not sure.

 

[Larks]

I'm not sure how out of round is the Arbor that goes through the Bridle? If you are not dealing with say more than 20-25 percent of the circumference being out of round, I'm not sure I would do anything more than filling in the hole with a screw as you mentioned (I suspect welding it would warp it too much, but I'm not absolutely certain about that because I'm not a welder.) I would then drill it for the Arbor as is.

However, if the Arbor is more out of round than that, you may have enough metal to turn it round on your drill press and then fix the Bridle and drill it for the smaller hole.

Gus

Running the verniers around it slowly it seems to be really just in one small area vertically as the lock would sit - so the cock has much more slop on that vertical plane than it does on the horizontal plane - though the horizontal slop is still far too much I’m sure. The majority of the arbour "seems" symmetrical enough to get a good alignment with the drill chuck.

But the more that I’m learning here now (and the better I see the mess that I have made through my photos) the more I think I’ll wait until I can get a hold of a machinist to put a decent edge finder on it to see what they can do themselves before I make an even bigger mess of it.

 

[Artificer]

Looking more closely at the fly notch in the tumbler neither side of it looks sharply formed, the back end being slightly angled and the front end the same but also quite rough, so I am sure they could profit from some gentle attention before I start on the fly itself. I do get the feeling that the fly sits slightly too far out from the tumbler, whether that is because of these edge issues, the arbour on the fly, the fly that it sits in or the outside edges of the fly needing attention I'm not sure.

Yes, I think the rounded point of the Fly is slightly too long. I think it is part of the reason the lock hangs up.

I think you might get some useful info from the following link, originally written by Forum Member George.

Lock Function (insightbb.com)

Gus

 

[FlinterNick]

Yes, I think the rounded point of the Fly is slightly too long. I think it is part of the reason the lock hangs up.

I think you might get some useful info from the following link, originally written by Forum Member George.

Lock Function (insightbb.com)

Gus

I agree with Gus, I keep referencing back to the fly and for some reason it just doesn’t seem geometrically even on all sides and at the point. On a good note flys are relatively easy to replace. Looking at One of my RE Davis locks, the fly is perfectly integrated with the sear (granted these are machined locks) the sear has a slight chamfer to avoid jamming up.

one thing I can see from your tumbler is that it looks a little rough on its outer edges that the sear engages, you would want to that to be polished up to clean surface for bearing, same with the sear nose.

 

[Clint Meier]

Having read through this entire post with much interest, I beg to ask a question. In Artificer's post #32 above, the photo (and in all others assembled and unassembled) seems to show that the inner tumbler shaft does not sit in the center of the hole in the bridle. This may just be due to perspective and that the photo was not taken in perpendicular alignment to the tumbler shaft, and that if it was, the gap of the hole may be more even than shown here. Mention was made as to filing down the shaft to make it more round than it is now, and of possibly drilling the hole in the bridle out and threading a screw shaft in and re-drilling the hole to a smaller size. If that is done, what needs to be done to insure that the inner and outer tumbler shafts are concentric (or in line) with one another on the opposite sides of the tumbler? It seems to me that if they are off and the holes in the lock plate and bridle are tight fits that binding will most likely occur. What am I missing here? Thanks!

 

[Artificer]

Having read through this entire post with much interest, I beg to ask a question. In Artificer's post #32 above, the photo (and in all others assembled and unassembled) seems to show that the inner tumbler shaft does not sit in the center of the hole in the bridle. This may just be due to perspective and that the photo was not taken in perpendicular alignment to the tumbler shaft, and that if it was, the gap of the hole may be more even than shown here. Mention was made as to filing down the shaft to make it more round than it is now, and of possibly drilling the hole in the bridle out and threading a screw shaft in and re-drilling the hole to a smaller size. If that is done, what needs to be done to insure that the inner and outer tumbler shafts are concentric (or in line) with one another on the opposite sides of the tumbler? It seems to me that if they are off and the holes in the lock plate and bridle are tight fits that binding will most likely occur. What am I missing here? Thanks!

Hi Clint,

Long story short, we are talking about bushing the too loose hole in the lock plate for the outward Tumbler Arbor and filing in the hole and re-drilling it in the Bridle, to make the hole size fit the inner Tumbler arbor better. Of course, both together would re-align the Tumbler to make it concentric with the lock plate.

Gus

 

[Artificer]

I agree with Gus, I keep referencing back to the fly and for some reason it just doesn’t seem geometrically even on all sides and at the point. On a good note flys are relatively easy to replace. Looking at One of my RE Davis locks, the fly is perfectly integrated with the sear (granted these are machined locks) the sear has a slight chamfer to avoid jamming up.

I agree with the emboldened sentence, but I think a good deal of that can be corrected when the Fly is thinned in width to allow the Sear Nose to correctly enter the Half Cock. The bottom angled edges may also be corrected more when addressing the too long length of the Fly. Still, the sides and bottom angled surfaces don't have to be perfectly even or symmetrical to work properly.

one thing I can see from your tumbler is that it looks a little rough on its outer edges that the sear engages, you would want to that to be polished up to clean surface for bearing, same with the sear nose.

There are a number of surfaces where there are still voids left in the metal from the casting process, that would not be there if the part had been forged from solid metal. Most of these should be smoothed for looks and function. Such smoothing will require fine filing and then Emery Cloth wrapped around files and/or stones to dress and polish them.

There are also too many sharp edges and burrs/filings in the parts now. All edges need to be "relieved" as machinists say or the edges very slightly chamfered by using fine files or stones. This to ensure the parts don't hang up when they work against each other and will operate smoothly.

Gus