Slow ignition Touch-hole size?

[rickystl]

The one thing I noticed with my vent liner is that I need to "pick" the vent hole after each shot. Without a vent liner, I only had to do it every 3rd shot or so. But other than that, I get good fast ignition. Rick. :hatsoff:

 

[Rifleman1776]

It is my belief that 2 charges that close together ignite as a single charge. (Photography through the muzzle convince me that the closer the priming to the vent the faster the ignition.)

Agree. :thumbsup:
Just looking at the touchhole of a loaded rifle with an inside cone liner will prove that.

 

[excess650]

If external coning aids flash efficiency from the pan, funneling the priming charge detonation inward to ignite the main charge than is it unreasonable to assume that the exact same dynamic occurs from the opposite direction when main charge ignites and pushes gas the other way?I believe that would be true if the internal and external "cones" were of the same shape and size.
Would not the absence of a funnel on the inside of the liner better inhibit the chamber pressure from escaping out the flash hole? As far as I know funneling aids pressure flow wither gas or liquid.
Mike D.

What I think MOST important is that the powder charge be as close to the priming charge as possible. This is best achieved with an internal "cone" allowing the barrel charge to be as close as 1/32" from the priming charge. Coning from the outside would make that distance at least the wall thickness of the barrel if no prime was allowed in the cone so as to prevent the fuse effect.....agree so far? Now if we use a radius (or parabola) to make our internal "cone"(the curve at the end with the vent), It becomes somewhat self blocking in regards to allowing blast OUT.

My earlier thought regarding the coned compensator port, much like a megaphone, enhancing flow FROM the smaller orifice, probably doesn't apply because the internal cone is effectively filled with powder. :hmm:

I need a beer :surrender:

 

[LRB]

That's odd Ricky. I only pick mine when I blow down the bore and find it obstructed, but that's another subject in itself. Most often, when I have picked after loading, I get a delayed ignition, and had a flash in the pan last year with my sights on a deer.

 

[M. De Land]

Well Wick, I saw where he proved banking the powder toward the flash hole in the pan and using Null-B sped up ignition.
I must have missed the one where he proved internal coning sped the process up by reducing by a few thousands of an inch the distance pan flash had to travel to the main charge or that it's shape had anything to do with it.
If I remember correctly in the pictures you refer to the pan flash was blowing gas and fire clear out the clean out hole on the opposite side of the test barrel.
Also, I get a little nervous when things that appear to be so "speak for themselves", for I have found such things, on occasion, to be untrue.
Actually what I'm trying to figure out is about gas escapement back out the vent after main charge detonation.
I currently think which ever internal shape retains the most pressure and still allows reliable ignition will be the best compromise for overall performance.
A test like the one I've proposed I think will answer some of the questions advanced in this thread.
I'm not sure being curious and questioning conventional thought about how or even if things actually work as excepted, constitutes over thinking. Mike D.

 

[Larry Pletcher]

Since we're looking at the value of a internally coned liner, let's look at the late English flint period. These makers were involved in an "arms race" -- actually an "ignition arms race". The top makers were trying to establish themselves as the maker of the fastest ignition time. You can name them as well as I.
I remember reading about cut-throat competition, law suits, etc. This involved the world's best locks as well as sophisticated breeches designed for a specific granule size. They spared nothing in this ignition race. My gut says they cared nothing about how gases exited the barrel - only how fast they could get the fire in. It seems logical to me that these English coned breeches were one part of the fastest these guys could come up with. And it is this type of liner that McKenzie and Chambers would have thought was best.

(BTW, In almost 30 years I have never timed a faster lock than an original Joseph Manton owned by Lynton McKenzie. In second place is another original lock made by Stoudenmyer. sp? )

Regards
Pletch

 

[LRB]

"I must have missed the one where he proved internal coning sped the process up by reducing by a few thousands of an inch the distance pan flash had to travel to the main charge or that it's shape had anything to do with it."

I don't know what you're saying. an internal coned liner reduces a lot more than a few thousandths, more like almost the entire wall thickness.

 

[Zonie]

Speaking of Joseph Manton and flintlocks, in the book "THE GUN", by W.W. Greener, 9th ed., page 227 says,

"The name best remembered among the gun-makers of this period is that of Joseph Manton, who was not only a clever and talented gunsmith, but an inventor not devoid of genius...
He produced the best of flint-locks, and fitted them with numerous improvements. The gravitating stops, to prevent accidental discharge whilst loading, were probably more highly esteemed than any of his inventions relating to self-priming and water-tight flash pans. Like all men of genius, he was occasionally absurd; one particularly fatuous invention of his was a vent-hole which allowed the air to escape but not to enter. He lost much money in litigation, and died poor at the age of sixty-nine..."

A question about the reason for Patented designs was raised. Was it for ignition reliability advancement or accuracy?

It was primarily for ignition speed and reliability.
This was during the time that wing-shooting using shotguns was very popular in England.

As anyone who has hunted flying birds with a shotgun knows, the speed and reliability of ignition is crucial to downing the game.
A mis-fire or delayed ignition equals a missed shot.

 

[Bill Knapp]

Jim Chambers, who participates on another site, explained that his White lightening liners hole is at what he considers minimum size, and he expects that it may need to be widened. This will depend on barrel wall thickness (distance from barrel face to charge in barrel) among other variables Thus just installing a liner and doing nothing more, may not be the answer. That said, all of my rifles are custom by top builders, excluding myself(as a top builder) They all have liners or are internally coned, and I have never had a problem, when I do my job. Sometimes I get an occasional flash in the pan, because I forgot to pick the touch hole, or over filled the pan causing a fuse effect, and delayed fire. I follow thru with, and try to do all the hints that Pletch has discovered with his gazillion frames per second photography, my only fault is banking the prime away from the touchhole, but thats from forty years plus of flintlock experience, and I use only FFFG or FFFFG in the pan.
P.S. My next two builds, I'm using one of Tom Snyder's internal coning burrs, just to see how it works.

 

[M. De Land]

Probably the differences in how liners are fit and installed.
I feel the proper way for a liner to be fit and installed is to follow the profile of the barrel groove diameter internally and flat of the barrel externally being flush with both. I feel a liner should not be made flat internally but rather ball milled or round filed to follow the curvature of the bore to eliminate both intrusion and voids above and below the center line that accumulate fouling and is hard to get to for cleaning.
This makes the liner thickness at the flash hole no more or less the thickness of the barrel wall had no liner been installed.
Coning both sides would definitely shorten the flash hole length but what I question is that this reduction would make any noticeable change in reliability or speed given what Larry's photos show of flash from the pan blowing across the width of the test barrel and out the cleaning hole.
I have a stainless liner factory installed in my match pistol that is not coned on either side.
If I coned it on both sides to the maximum degree I was referring to in the previous post I might reduce the flash hole length by .125 total and I seriously doubt I would cone each side to .0625 depth.
I'm just not convinced at this point that the slight shortening of the flash channel would have much if any effect on speed of ignition or reliability if the vent is properly located and of the right diameter.
I think any benefit derived from external coning has more to do with funneling the pan detonation into the main charge than does the flash hole length reduction.
For the same reason I think interior coning does not retain pressure as well when the main charge detonates. Mike D.

 

[LRB]

That clears it up and I see your point, however, the internal cone does speed ignition and increases reliability from a simple hole in the barrel wall, and I don't see where any extra pressure loss should be of concern. Any loss of pressure would be consistent to the particular gun, and accuracy load for it. If one was swapping different vent liner types from session to session, it MAY be possible to see an effect in POI from pressure variation, But without measuring for pressure variation, we would not know if a change in POI was from pressure or ignition speed. I seriously doubt the pressure could vary enough to notice. As far as an external cone, it does funnel the flash increasing reliability, but I doubt any speed advantage over the internal cone. The external cone on my liner is very shallow. Probably no more than .020 deep. Just enough to catch more of the flash.

 

[rickystl]

Hi Wick. Historically, my procedure was the same as yours. But for some reason, the vent liner in this rifle doesn't like me unless I treat it the way it wants. :haha: One mistake I was doing was to use one of those piano wire deals from Dixie. Works great for nipples, but it's too small for the vents in flintlocks. So started using the the right size forged ones you typically see, and that worked much better. Actually, I started picking the vent AFTER firing, and then blow down the barrel. Have not had a problem since. :idunno:

DARN! Did the deer get away? Rick. :hatsoff:

 

[M. De Land]

I have been using ones made from soft black wire Ricky with a rounded hemisphere end but think I will change the end to flat.
The black wire is a snug slip fit through the flash hole and punches out any foul ahead of it. The soft steel does not change the hole profile any by swagging like a hardened steel one might.
Also the hard sharpened picks tend to go through the vent and hit the far barrel wall, probably making some scratches or impact dents in it over time. Mike D.

 

[Bill Knapp]

I use a historically correct paperclip!

Bill

 

[rickystl]

Soft black wire? Never thought of that. I'll have to try that. I know the type of wire you mention. Thanks for the tip! Rick. :hatsoff:

 

[M. De Land]

If the diameter is close they should be fine but they are a good bit harder than soft black wire. Mike D.

 

[Herb]

I just shot my first shots through a .45 Lancaster I made with a Chambers Classic flintlock and a White Lightning liner. The first four shots were flashes in the pan, with the .050 or so liner. The field cure for that is to use the 4F priming powder and tip it into the flash hole. My big paperclip would not go into the hole, so couldn't pick the vent. I ran out of 4F and primed twice with Goex 3F, but got hangfires both times. Went home and drilled the flash hole to .070.

 

[Larry Pletcher]

Hi Herb,
If my memory serves, I think Jim told me at Friendship that they ship with a hole at.055". Might be .053". I know a 1/16" bit won't pass.

Regards,
Pletch

 

[ApprenticeBuilder]

My rifle gets loaded with 3f and primed with 4f and has the Chambers liner drilled to .070 and is as fast as can be without dumping powder while I load, my NWG on the other hand is loaded with 2f and primed the same but the liner on that one is drilled out to .073 for speed of ignition.

Both of those muzzle loaders are fast.

I always pick the vent before the pan is primed, always

 

[azmntman]

"ALWAYS?" really? :blah: