Touch hole liners??????????

[JLE]

Sorry I did not click on the link TOF posted,I see how the old-timers done it now. I wonder if Jacob Dickert had one of these tools. maybe the Continental Rifles did have coned touch holes after all. We still never will know for sure.

[jwh1947]

Advocatus diabolcius certainly knows how to start a discussion.  Touch-hole liner issue outdoes all other recent threads two-to-one or better.  You know what that tells me as a teacher? I hit a nerve...I hit a true area of controversy, or the fiery  discussion would not have ensued.  Carry on, men and women.  I am back to square one...most of you speak from reason and intelligence, but yet I think mechanical and physical variance and individual shooting ability are two areas of deviation that are most important and most difficult to control or otherwise account for.

No problem with wanting the best, the fastest, the most efficient, to minimize or lower variance of above, but, in the end, it may be as Dad said, "Usually it ain't the arrow, but it is the Indian."

[keweenaw]

The counter bore tools I make are sized so that one can easily install a White Lightnin' liner if the touch hole burns out.  For example if you cut a internal cone with my medium counter bore and the touch hole gets enlarged, you just drill it out with the appropriate size drill for the 5/16" WL liner, thread appropriately and install the liner.  My small counter bore corresponds to the 1/4" liner and the large to the 3/8" liner. 

Tom

[Larry Pletcher]

Jim hasn't mentioned this but he has a fix for those who dislike liners because of they look.  He makes a version that looks like the barrel - instead of the shiny liner showing up different than the barrel.
Regards,
Pletch

[The other DWS]

hardened regular steel rather than stainless?

[keweenaw]

Jim also makes his liners in carbon steel.  They aren't hardened as you couldn't file them down flush if they were. 

Tom

[t.caster]

I recently took delivery of 10 more new WL liners in various sizes for future builds and replacements, although I don't think I've ever had to replace one yet. So now you know where I stand on this issue.

[Dr. Tim-Boone]

This thread must be nearing an ALR record.

Pletch I have started a conversation with our GA Tech rocketry people to find someone who specializes in the use of ffffg for igniting small rockets....it is an igniter of choice. Perhaps one of them is an engineer in the field and can suggest some experimental methods to use to understand more of the touch hole dynamics.....

BTW showed my professor friend (Information archiving tech) in the next office the latest Muzzleblasts articles about Martin's station. He is a descendant. He had a long conversation with me about building guns. He then called Jim Chambers and purchased a seat for himself and one for his son in Jim's course on building a gun from a kit in May!! Another TWO are about to get hooked on traditional ML!!!! Evangelism!!

[g.pennell]

Amen, Brother Boone! 

Greg

[JTR]

This thread must be nearing an ALR record.

And over a touch hole none the less! 

John

[Larry Pletcher]

This thread must be nearing an ALR record.

Pletch I have started a conversation with our GA Tech rocketry people to find someone who specializes in the use of ffffg for igniting small rockets....it is an igniter of choice. Perhaps one of them is an engineer in the field and can suggest some experimental methods to use to understand more of the touch hole dynamics.....

Tim,
I'd be interested in anything that we can learn.
Regards,
Pletch

[Daryl]

Interesting observation- I remember one about a Jacob Kuntz rifle that went a few more pages - 5,000+ reads, wasn't it?

[Darkhorse]

I am not from a part of the country that has a wealth in old guns to examine nor much local knowledge. So all I know, or think I know, is derived from my own efforts to make slow guns shoot faster and my background in the Aeorspace structural manufacturing buisness.
I always use a WL. I always slightly chamfer the outside. I always drill one number drill at a time ( with much shooting between each drilling) until I get my required results.
I install my flints bevel down for a couple of reasons.
I want to try and maintain the same angle of clearance on the flint through many knappings. I want and expect the the hardened friz to curl off the cutting tool (fllint) and drop into the pan.
The lower the flint can strike the friz and still perform properly the less time there is for all the mechanical movement of the lock itself to affect my shot. The flint still strikes with force the friz and this causes movement. Period.
I am not a top of the line marksman and getting less so each year. I need all the help I can get with a flintlock. And speed is the help I need most. Oh yeah. A new set of eyes would help an awful lot too.

[smylee grouch]

Daryl, did those Jacob Kunz rifles have linners?  I am a self proclaimed Kunz nut so would be interested to know if he used linners or a drilled hole.    Gary

[Daryl]

I believe the maker used a whitelightening liner - good question. The rifle was a compilation of the two specimines in the Museum in New York.

[Dphariss]

Pg 77 "British Military Flintlock Rifles" Bailey

"Isaac Nutimus for bushing his Rifle 1/-."
 
Ledger at Shamokin (an Indian Town) for 2 June-15 Dec, 1759
Cannon vents used to enlarge as well and they were also "bushed".

Dan

[Daryl]

Platinum was popular for 'bushing' vents in England, I believe - even held over into the cap-lock era with what some people call a 'blow-out' plug. Forsyth describes in 1862, the platinum 'vent' on the bolster of cap-locks eleviated hard loading, and 'softened' recoil somewhat.

[Joe S]

From what I can tell by looking at photographs, touch hole bushings are fairly common and go back at least to the early 1700’s.  My impression of these bushings is that they are generally too small to have any significant internal coning, and are most likely repairs for a burned out straight hole.  I’ve only seen one late English gun that apparently had a coned vent liner as we think of them today.

My impression is that for the general run of the mill American flintlock, internally coned vent liners were extremely scarce to nonexistent.  Is this an accurate observation?

[rich pierce]

Impossible to know.  Techniques were not documented, and few original American flint guns exist in a condition where this could be ascertained.

[Joe S]

Rich – I’m assuming that an internally coned vent liner would have to be relatively large, say at least ¼” or so, and that small bushings, say in the 1/8” range most likely would have straight holes, and were replacement bushing for a previous straight hole.   If that were true, then we could guess with some accuracy whether the liner was a bushing for a straight hole or an actual internally coned vent liner.  What do you think?

[Rootsy]

A truly fascinating subject that I seem to have come late into.  I only wish that I was as much of a sponge back when some good Professors were trying to teach me important principles as I am these days.  I believe I retained enough to be educationally dangerous.  Though I do not have nearly the experience with the flintlock and it's mechanical attributes as most of the folks who have previously posted.

This is more of a fluid and thermodynamics puzzle than it is purely mechanical.  The touch hole is an orifice for all practical purposes and we are trying to flow a hot gas through it in a shaping manner in the shortest time frame possible.  To get to the nitty gritty there are entirely too many Greek characters involved and I'd need an entire chalk board...

Think of the principle this way.  We are creating a chemical reaction on the outside of the barrel (O2 + powder + heat = gas + lots of heat + other compounds).  Creating an exothermic reaction resulting in a hot gas.  We are attempting to shape the expanding gas column with the pan and channel it into the vent hole,  accomplished by the shape of the pan.  This in order to get that hot gas as quickly to the main charge as possible while maintaining as much temperature as possible to raise the temperature of the nearest amount of charge above it's ignition point.  Simple.

For all intensive purposes I would treat this as a fully turbulent flow situation.  

There are a lot of mechanical characteristics of an orifice that impede flow of a compressible fluid, one being the inlet shape.  A sharp corner will impede flow.  Length and diameter of the orifice will also.  Thus a smooth transition into the orifice as well as a short channel will keep the flow velocity up rather than diminish it.  Better than simply chamfering the outside would be to have a radial inlet transition from chamfer to vent orifice.   How much better is difficult to quantify by speculation.  But in essence any gradual transition to the final orifice diameter is better than an abrupt perpendicular, sharp transition.  

By tapering or flaring the inner side of the orifice I see this as attempting to expose as large a surface area of the main charge to the hot fluid as possible.  Depending upon granule size I would venture to say  more or less most of the chamber on the back side of a shaped vent would be filled with the main charge.   If that is the case the inner configuration would play a part in a secondary chemical reaction.  That being the ignition of the charge in the liner vs the overall main charge.  The small amount of powder in the vent chamber being a "booster" or intermediate charge which actually ignites the main charge.   The shape of the chamber in the vent would then be responsible for shaping the direction of that secondary charge.   More or less a nozzle.

I would venture to say that the addition of a secondary ignition chamber (the shape of the inside of the vent liner) and subsequent shorting of the orifice itself (the vent hole) would contribute more so to decreased ignition time than the exterior shape but again that is difficult to quantify by speculation.   We can go so far as to study the placement of the vent inlet relative to the pan... Then we need to study how the pan itself shapes and directs the gas column.

Just some food for thought and discussion.  Hopefully not too "techie"...

[rich pierce]

Arguments against internally coned touchholes on period flint rifles in America:

It's pretty clear, I think, that muskets had straight touch holes, and armies considered reliability important.  

There are plenty of period references for self-priming touchholes.  It would not seem an internal cone is necessary if the touchhole is that large.

Anybody actually growing up shooting only flintlocks and never shooting percussion or cartridge guns, probably did not have the sense that ignition was slow.  I propose this is a modern thought; natural for those of us who have experienced faster ignition.  We want to 'fix it".  They did not know they had a problem, IMHO.

Arguments for internally coned touchholes on period flintlock rifles in America:
The tools to achieve this existed.

[The other DWS]

wonder if it was an option, like engraving, inlays or fancier wood.

which could start a whole 'nother thread about what WAS available based on documents

[Dphariss]

Platinum was popular for 'bushing' vents in England, I believe - even held over into the cap-lock era with what some people call a 'blow-out' plug. Forsyth describes in 1862, the platinum 'vent' on the bolster of cap-locks eleviated hard loading, and 'softened' recoil somewhat.

Gold was very popular. As you likely know it was actually beaten into a iron liner that screwed into the barrel or breech.
The use of Platinum dates to the very end of the 18th or early 19th centuries when a process was discovered to make Platinum malleable. I had a print out of a history of this someplace but would have to dig it out.
Its on the WWW someplace.

Dan

[Cody Tetachuk]

................ the inner configuration would play a part in a secondary chemical reaction.  That being the ignition of the charge in the liner vs the overall main charge.  The small amount of powder in the vent chamber being a "booster" or intermediate charge which actually ignites the main charge.   The shape of the chamber in the vent would then be responsible for shaping the direction of that secondary charge.   More or less a nozzle.

I would venture to say that the addition of a secondary ignition chamber (the shape of the inside of the vent liner) and subsequent shorting of the orifice itself (the vent hole) would contribute more so to decreased ignition time than the exterior shape but again that is difficult to quantify by speculation.   We can go so far as to study the placement of the vent inlet relative to the pan... Then we need to study how the pan itself shapes and directs the gas column.

It's always been my belief that this is the general idea behind Nock's patent breech except that the "secondary ignition chamber" is the anti-chamber rather than the internal TH cone but the same principle applies.