Lock positioning

[Uncle Alvah]

I have been reading some on lock positioning. Seems to me, perhaps because this is my first build, that the positioning of the lock is pretty well fixed. The touch hole is just forward of the breech plug. The pan is centered below the touch hole, and the pan connects to the lock plate. everything seems kind prepositioned to me. Yes?/No?

[rich pierce]

Well, on a longrifle a few degrees here and there seem to matter.  Let's pivot the lock around the axis of the touchole. The forward lock bolt in the nose of the lock must pass below the barrel but above the ramrod hole.  Yet within that narrow web there is a range that will determine the angle of the lock and where the tail of the lock rests.

Now if you are working with a precarved stock, then you are constrained.  But if a blank, you can not only position the tail of the lock where you want it on the wrist, you can place the wrist where you want it on the lock tail.

[WKevinD]

Don't forget the location of the web of wood where the front lock bolt runs thru below the barrel and above the ramrod channel, that will set the angle of the lock.
Kevin

[Scota4570]

I've been head scratching on this one too.  It also seems that one need to use a lock that matches the breech diameter.  A lock with a step down to the pan would work with a fat barrel.  No step down then a thinner barrel? 

[rich pierce]

What is a step down to the pan?

Larger barrels need larger locks because all dimensions of the stock at the breech are correspondingly large.  Don't want a small lock swimming in a huge lock panel, or a V-shaped underside of the stock in the trigger/trigger guard area to allow decently thin lock panels.

[flehto]

Considering all the correct previous replies, I'd like to mention that some locks "fit in" better than some other locks. Seeing I only use Chambers' locks, the 3 locks of his that really align well are his Golden Age, Late Ketland and the Dale Johnson....mainly because of their lower "tail".  Some of his other locks are probably OK in this respect, except the large Siler which has always given me some trouble w/ alignment causing  some builders to lower the Siler's "tail".

The top pic is that of a Golden Age, the middle lock is a  Late Ketland  and the bottom lock is a Dale Johnson.....Fred

[Chowmi]

I do not have particular expertise, but can pass on what Jack Brooks taught me recently.
3 priorities:
Touch hole location

Tail of the lock location / angle

Then, nose of the lock for the lock bolt.

Why is nose of the lock last?  Because the tail of the lock plate flows into the wrist, defining part of the architecture. You have some options for solving a lock bolt that does not pass cleanly through the web between rr channel and barrel. File a notch in the bolt so the ramrod can pass through, or file a notch in the barrel for a bolt that is too high (within reason of course). Both of these were done on originals.

In other words, he prioritized architecture over getting the front lock bolt cleanly through the web.

These were his priorities based on architecture being the foundation of a good looking gun.

Cheers,
Norm

[PPatch]

"... that the positioning of the lock is pretty well fixed."

Within narrow limits it is fairly fixed, but there is some wiggle room. Once you locate the touch hole you key off of it as has been mentioned. The wiggle is in where you place the nose and tail of the lock. If you intend to have a forward lock bolt it should go through the web under the barrel and above the RR channel. If you aren't going to install a forward bolt then no worries about positioning the lock for one. The tail should be a hair above the centerline of the wrist. If you can't get it there then put the tail on the centerline.

Once you determine where you want the lock, and have filed a slight bevel around its peripheral, and removed the lock internals, then lightly clamp it in place and begin your initial cut into the wood defining the outside of the lock. The bolster goes in first, you are aiming to have the lock pan centered on your touch hole and the hole in the "sunset" position relative to the pan. Inlet the bolster and lock plate until the bolster is snug and square against the side flat of the barrel. "snug" means you can't get a slip of paper between the bolster and barrel. If you have to remove wood off the lock panel as the lock plate goes deeper, do so. Once that is done begin to add the lock internals and inlet those. Remove as little wood as possible, as this is a weak area, and you want as much wood remaining as possible as long as the lock functions freely once you are finished. It is the same with the triggers, leave as much wood as you can as long as the triggers function as they ought to.

Your double-set triggers key off of the lock, specifically the sear bar. Be careful of where you inlet the trigger bar, that little adjustment screw hole on the bar between the triggers should be positioned immediately above the sear bar. Remember that when inletting on a curved surface you begin at one end, usually the forward end, and inlet to the other end, and that the adjustment screw hole will move a tiny bit forward as you inlet the trigger bar.

dave

[David Rase]

I second what Chowmi (Norm) posted.  Touch hole alignment and lock tail positioning are king to function and architecture.
David

[Acer Saccharum]

Touch hole alignment and lock tail positioning are king to function and architecture.

Exactly right.

The touchhole can be up or down a little. There is not much wiggle room fore and aft if you're using a liner. Once you have the touch hole located on the barrel, you can rotate the lock around the hole a little while keeping the pan centered on the hole. Then you can see how the front lock bolt lies. At this point, you can move the lock only incrementally, either up or down, front or back only by 1/32" or less without losing excellent touchhole placement.

On a big barrel, the flat is wide, and you can move the touchhole up or down a little. That sometimes helps getting the lock tail where you like it. Sometimes you need to file a groove across the bottom flat of the barrel for the front bolt to pass.

I don't try to line the fence up with the barrel breech. You see antique rifles with the fences all over the place. I'd much rather have a smooth face breech plug than to groove it out for touchhole placement. That is my personal preference.

[Bigmon]

This is a very interesting discussion and something I have only become aware of recently.
It seems one of the most important thing to do is get the correct lock for the size of the barrel.
This should not require thinking about every time?
For as long as these guns have been built should there not be some kind of chart saying for example:
Large Siler use a 13/16" thru 15/16" barrel.
small Siler use 3/4" thru 13/16"
Early English, ETC ETC ETC??
I am considering straight barrels, but even swamped or tapered would apply if the dimension were at the lock area.

This seems to me to be pretty basic and something the lock manufacturers would list.  Of course only as reccomendations, but it would be very helpful to use novices???
I can't wait to hear some opinions on this.

For example I have a 13/16" barrel about ready to start on a build.
I have an L&R Classic, a Large Siler, a Larry Zorn Continental, a Chambers English and a Davis round faced lock, all one hand in my parts and can use any of them.

Which would fit that barrel best, not considering the rifle style, which is a Bucks County.

Oh so interesting, yet complicated.
I love it.  Makes me think.
Bigmon

[Mike Brooks]

This is a very interesting discussion and something I have only become aware of recently.
It seems one of the most important thing to do is get the correct lock for the size of the barrel.
This should not require thinking about every time?
For as long as these guns have been built should there not be some kind of chart saying for example:
Large Siler use a 13/16" thru 15/16" barrel.
small Siler use 3/4" thru 13/16"
Early English, ETC ETC ETC??
I am considering straight barrels, but even swamped or tapered would apply if the dimension were at the lock area.

This seems to me to be pretty basic and something the lock manufacturers would list.  Of course only as reccomendations, but it would be very helpful to use novices???
I can't wait to hear some opinions on this.

For example I have a 13/16" barrel about ready to start on a build.
I have an L&R Classic, a Large Siler, a Larry Zorn Continental, a Chambers English and a Davis round faced lock, all one hand in my parts and can use any of them.

Which would fit that barrel best, not considering the rifle style, which is a Bucks County.

Oh so interesting, yet complicated.
I love it.  Makes me think.
Bigmon

It's the barrel size that is the big problem. Bucks Co. guns had larger barrels.

[Bigmon]

That's the kinda stuff I gotta learn.
But I bought the stock with the butt already shaped as is and the barrel channel already routered.  So someone besides me needs to learn that also, or there should be no stocks available in the Bucks style with a 13/16" barrel?
But that is another subject.
Please just assume that I have the correct style stock for a 13/16" barrel.  What would be the ideal style /size lock of those I have available for the 13/26" straight barrel.

It is surprising to me that each lock available  doesnt have a certain size of barrels it is best suited for, and that isn't a basic thing to do when matching a lock and a barrel??
Thanks to all

[TommyG]

I ran into this issue on a Dickert rifle I am currently building.  I am using a B weight barrel.  Just couldn't seem to find the a lock plate profile that would work and remain close to RCA 48.  I ended up using a Chambers gunmakers lock and cut to fit.  Now I am certainly no expert, this being build No.3, but what works for me is to create a scaled drawing on craft paper, and work out the relationships between lock, trigger, triggerguard and buttplate.  From there I cut the template for the stock knowing that the hardware I have will work.  I learned the hard way in my early woodworking days to never start a project without the hardware in hand.  I have not built enough of these rifles yet, so I try to do step 5 before step 2 and assume nothing. 

[WadePatton]

I second what Chowmi (Norm) posted.  Touch hole alignment and lock tail positioning are king to function and architecture.
David

I hate to be redundant, but I fully concur and the story that is told most wins. 

[Mike Brooks]

That's the kinda stuff I gotta learn.
But I bought the stock with the butt already shaped as is and the barrel channel already routered.  So someone besides me needs to learn that also, or there should be no stocks available in the Bucks style with a 13/16" barrel?
But that is another subject.
Please just assume that I have the correct style stock for a 13/16" barrel.  What would be the ideal style /size lock of those I have available for the 13/26" straight barrel.

It is surprising to me that each lock available  doesnt have a certain size of barrels it is best suited for, and that isn't a basic thing to do when matching a lock and a barrel??
Thanks to all

Ok. You'll find barrels that small on very late flint guns. they generally have English export locks about 4.5" long give or take maybe 1/4" or so.

[WadePatton]

Along those lines of "mixed and matched parts" as are commonly sold in "kit" form for the novices and new-timers, I used to get all worked up about it.  I felt it was a disservice to the historical aspects of our pursuits.

Later I got over it.  It appears to be a way to separate those who have done their homework from those who haven't. To which I yet have mixed feelings but the thing we cannot escape is that "kits" _AS ISSUED_ often do not have the "proper" parts in per historical evidence, but that they can usually be "customized" for the buyer if he/she goes to the trouble of finding out before the purchase.

Lots of reasons for it, and there's no point in discussing that. Just always be aware that any kit is only the expression of the ideas of the company selling it and may or may not fit what students of the rifle (whichever school/time) feel should actually be in them.

Exceptions of course for some of the outfits, like Mr. Kibler for one example.  So just be very aware and realize that it takes some time and study to really get any school or style of gun proper. 

Happy positioning--also note that folks here will be glad to help right down to the fine line-just post the pics as you go. Not that everyone will fully agree.