touch hole in "tub drain position" example

[WadePatton]

Was just perusing the web for photographs of flintlock rifles and found this shot of a touch hole that, to my limited knowledge, ain't where it's supposed to be. 

Yes it's an imported replica, but aren't some truths self-evident?

[490roundball]

yeah - too low, and it can't be any lower

I was in a big box sporting goods store once and looked a every example of a certain mass produced flinter on the rack.  every touch hole was in a slightly different spot - none of them correct.

[Gene Carrell]

Self-limiting on priming powder capacity; unless you prefer a fuse.

[pathfinder]

I've fixed these by putting in a 3/8ths liner.

[mattdog]

"...Self-limiting on priming powder capacity; unless you prefer a fuse."

Some people do.  The following is a true story.

We built and shipped a beautiful flintlock gun with perfect touch hole position To a customer in Oregon.  A week later he called, I could tell by the tone of his voice that he wasn't happy.  The conversation went something like this:

him: It's a nice looking gun but you guys screwed up on the touch hole.

me: I believe it is about an eighth inch above the bottom of the pan so-

he interupted me: yeah, that's the problem, this gun will never go off.

me: I started to explain about the sunrise position of the touch hole being the perfect and acceptable place for when he interupted me again -

"Hey, sonny, don't try to fast talk your way out of this.  I've been shooting flintlocks for 20 years and I know a thing or two about them.  I know that this gun will have problems.  What do you plan to do to fix it?"

I told him to go out and shoot it and if it didn't go off to his satisfaction I would buy it back from him, no questions asked.  I never heard from him again.  It must have worked and I believe that after twenty years of shooting flint he may have learned another thing or two about them.
 
 
 

[Hungry Horse]

A few years ago I was asked to examine a revolutionary war musket that was constructed supposedly in Pennsylvania, from a mish mosh of French gun parts imported during the war. The touch hole was well below the edge of the bottom of the pan. A simple trough was filed in the edge of the bottom of the pan giving the priming flash access to the main charge. Somebody fought a life, or death, war with this weapon, HELLO! Some times I feel we are all so busy making sure everything is perfect, we forget to learn to shoot what we have.
 Another old flinter I examined had a low touch hole, but some gunsmith had ground a recess into the outer portion of the pan, that allowed the prime to  stay away from the touch hole. It shot just fine that way.

                               Hungry Horse

[Joe S]

Larry Pletcher’s experiments have conclusively shown that vents located at the top of the pan and at the bottom of the pan have identical times for igniting the main charge.


Vent Position                                   Time to Ignition (seconds)

Low Vent                                            0.038
Level Vent                                          0.036
High Vent  (0.030” above top of pan)    0.037


http://www.blackpowdermag.com/featured-articles/part-6-high-and-low-vent-experiments.php
http://www.blackpowdermag.com/featured-articles/post-2.php

[Acer Saccharum]

Has anyone ever tried a lump on the bottom of the frizzen?  A lump that would cover the touchhole when the frizzen is closed, and leave the hole completely clear when the frizzen lifts?

[Jerry V Lape]

It is such a shock to the system when something you think is an absolute truth turns out to be absolutely wrong.  Thanks to Larry Pletcher we now know based on measured test results with high speed cameras and careful experimentation that hole placement is just as good in the photo at the beginning of this thread as the sunrise position at the top edge of the pan, and that powder piled against the touch hole actually is better than powder piled at the opposite end of the pan.  But I bet there will be great resistance to accepting it for decades.  

[Dphariss]

Has anyone ever tried a lump on the bottom of the frizzen?  A lump that would cover the touchhole when the frizzen is closed, and leave the hole completely clear when the frizzen lifts?

I think the English called them vent wipers.

Some are vented others are not.



The rifle lock casting from TRS shows no sign of being vented. Though it is cupped on the vent side like the Manton double in the top photo.
Would likely be detrimental with a outside coned vent.
Dan

[Dphariss]

A few years ago I was asked to examine a revolutionary war musket that was constructed supposedly in Pennsylvania, from a mish mosh of French gun parts imported during the war. The touch hole was well below the edge of the bottom of the pan. A simple trough was filed in the edge of the bottom of the pan giving the priming flash access to the main charge. Somebody fought a life, or death, war with this weapon, HELLO! Some times I feel we are all so busy making sure everything is perfect, we forget to learn to shoot what we have.
 Another old flinter I examined had a low touch hole, but some gunsmith had ground a recess into the outer portion of the pan, that allowed the prime to  stay away from the touch hole. It shot just fine that way.

                               Hungry Horse

One must remember that muskets were not particularly high quality and that the Committee of Safety stuff was was often very crude. I think many were stocked by people with just enough training to get the parts in the wood. But they were not concerned with how they looked. Then these same people thought they could make Kentucky rifles after the War with predicable results.
The low vent will likely gas cut the pan in any event. Other than that Larry's tests show its not of much import from the standpoint of ignition. But the better grade guns usually have a vent positioned like that in the photo of the Manton. If nothing else it looks better.

Dan

[Joe S]

Has anyone ever tried a lump on the bottom of the frizzen? A lump that would cover the touchhole when the frizzen is closed, and leave the hole completely clear when the frizzen lifts?

What is the purpose of this lump?  Pletcher’s data also shows that having powder next to or even covering the vent gives the highest ignition speed.  If the lump kept powder away from the vent, it could conceivably retard ignition.

[WadePatton]

I was only able to find Pletcher information on the position of powder in the pan.  I didn't find the other aspects he has tested.  I trust his findings. 

Yes it appears that the wiper would bank away and testing (that i found) has shown that to be contrary to the hot flash we desire.

So, pursuant to Pletcher's testing wrt high/low holes:

Do any modern builders (besides mass-production outfits) poke the touch hole at the very lowest point of the pan?

[Larry Pletcher]

I was only able to find Pletcher information on the position of powder in the pan.  I didn't find the other aspects he has tested.  I trust his findings. 

Wade,
The high vs low vent test is in Part 6:
http://www.blackpowdermag.com/featured-articles/part-6-high-and-low-vent-experiments.php

I should mention that the testing I did was two fold.
1.  I wanted to test the old idea that banking the priming powder away would help ignition speed.  I found this to be false.  The closer the priming,  the faster the ignition.

2.  I wanted to test the high vs low vent locations.  Before this, I would have gone with tradition and thought the higher (level with pan) vent would be faster and that a covered vent would be even slower.  This came, as it often does, with discussions at Friendship. I was in Mark Silver's booth listening to Mark and Gary Brumfield.  Gary related that he and Wallace had recently seen originals with very low vent locations - too low to be accidental. I told him that that could be tested.

The result was that I timed a level, low, and high position. And also timed these positions with priming close to the vent, middle of pan, and banked away from vent.  My gut now says that regardless where the vent is, I want the priming very close to the vent, in fact against the barrel.  In the low vent test the priming covered the vent, however I did not attempt to fill the vent.

BTW, my thinking is that hang fires are not caused by a vent filled with powder.  A vent filled with fouling is quite another story..

Best Regards,
Pletch

[Jerry V Lape]

I doubt any do that deliberately.  It probably occurred in this instance as a result of barrels being finished out completely in one part of the manufacturing and the machine inletted stock in another.  Placing the hole low in the pan has the added problem of putting the mainspring into the barrel channel more frequently as it reduces the clearance gained by dropping the pan that extra 1/8th of an inch or so.  

[Pete G.]

Has anyone ever tried a lump on the bottom of the frizzen?  A lump that would cover the touchhole when the frizzen is closed, and leave the hole completely clear when the frizzen lifts?

...and what is the purpose of the groove in the pan cover of the Siler locks (which is the exact opposite of the lump)?

[Joe S]

Pletch – I find these images from your vent position test compelling:


High Vent



Level Vent



Low Vent




Although the time to ignition is the same with all vent positions, the flame front in the barrel seems to increase from high to low vent position.  I’m wondering if this could affect how uniformly the flame front moves through the main powder charge.

With a low vent, would you get more consistent ignition of the main charge?  This could be tested by using a full length barrel, and measuring muzzle velocity.  If vent location has an effect on the uniformity of ignition of the main charge, it would show up as a decreased standard deviation in the muzzle velocity.

 Have you ever conducted this test?  

[Michael]

OK.? So the the touchole at the bottom of the pan works better than the 'sunset' position? Yes/no?

[Joe S]

Without further data all we can say for sure is that the time to ignite the main charge is identical for the two positions.  The photographs are compelling, but not definitive.  Pletch needs to cough up some data on muzzle velocity.

[Larry Pletcher]

I need to correct the labels on the three photos. These pics are NOT different vent locations. They came from Part 3 that deal with the position of prime in the pan. All photos are of .5 gr of null B. top pic has prime banked away. Middle pic had prime located in center of pan. Bottom pic has the prime pushed up against the barrel. The vent location was the same in all three pics. The variable was priming location in the pan.

To answer the last question, there was no statistical advantage in a high, medium, or low vent in this test.  Another way to put it is that placement of priming powder in the pan is a bigger variable than vent
location.

Joe is correct when he says that the times are basically the same. However, the timed tests were compared with priming all placed against the barrel while the photos show different priming powder locations. Make sure you aren't confusing vent locations with priming powder location.

Regards,
Pletch

PS Part 3 has a better explanation that what I wrote here.

[greybeard]

Has anyone ever tried a lump on the bottom of the frizzen?  A lump that would cover the touchhole when the frizzen is closed, and leave the hole completely clear when the frizzen lifts?

I could be wrong but I believe Joe or John Manton did it .
Of course I have been in error before, but not very often.
Bob Reader

[Joe S]

OK.  Now I’m confused.  From this link:  http://www.blackpowdermag.com/featured-articles/post-2.php

“….. All earlier photos that I took were with the vent in the “level” position. The purpose of those photos was to examine other variables. Here the only variable will be the height of the vent. I took three photos at each of the following vent locations:

a. vent located .030” above the top level of the pan
b. vent located level with the top of the pan
c. vent in the bottom of the pan…”

And these are the captions on the photos:

"Here are the photos of the vent .030” above level with the pan top:
Here are the photos with the vent level with the pan top:
Here are the photos taken with the vent at the bottom of the pan:”

[Larry Pletcher]

Joe ,
Now I get it.  We're looking at 2 different studies.  I was refering to Part 3 of the original tests:

http://www.blackpowdermag.com/featured-articles/photography-through-the-muzzle-part-3.php

In that phase the variable was the positioning of the priming powder in the pan.

------------------------

You are refering to "Pan Vent Experiments Continued":

http://www.blackpowdermag.com/featured-articles/post-2.php

In this phase the variable was, in deed the vent location. I'm sorry for the confusion.  We were talking about different tests.
Regards,
Pletch

[Captchee]

I seem to recall reading that the lump shown  in the photos that Dan posted , was an attempt to be able to increase the  flash of the pan by allowing  more powder  to be applied to the pan  while at the same time insuring that the powder did not cover the flash hole .
 If we look at self priming pans , we also see a gate  with a hole in it .
Why ??
Well it allows the powder from the main load to enter the pan during loading .
Yet at the same time when the  frizzen is struck , the gate wipes the powder away from the face of the flash hole . Thus insuring  no fuse   burn type of ignition .

 On the guns I build , I place the flash holes high  because I have found that location to provide the best and most consistent ignition .
 Now don’t get me wrong . I love tests and I often find it very interesting  when someone applies modern technologies to  test the application of  early techniques.

 However . Regardless of how those test turn out . I don’t think  we should be  discounting their own experience .
  How many of you have experienced a fuse burn in a flintlock ?
 How about slow ignition  or poor consistency .

 Probably if you have shot flintlocks for any length of time , you experienced all of the above and more . You also worked through the problem and deduced ways to  reduce the frequency of that happening.

So while these test may show  that banking  your powder against the flash hole , over filling the pan  or  placing the flash hole at the very bottom of the pan  shows no difference in ignition speed . Im betting that for most  ,to include myself , your practical and actual long term application  has  told you a differently

[Larry Pletcher]

Whenever discussions like this occur, I worry that by looking at a single set of photos, graphs, or test data, that a conclusion may be drawn without looking at the body of data as a whole.  To make sure that the information here is not misunderstood, I printed below the conclusions I drew from these two experiments. From the first 6 part article “Pan Vent Experiments”:

-------

The last conclusion involves the reason for this whole experiment - proper location for the vent in relationship to the pan. I found that the location of the vent in relation to the pan is far more forgiving that we have believed. Tests when the vent was extremely low or high both gave quick reliable ignition. A look at the chart below shows that all vent positions gave fast ignition when primed close to the vent (This is what we learned in the preliminary tests.) Also all vent positions gave uniformly poor performance when the priming powder was banked away from the vent.

--------------------------Banked way----------------Level Prime----------------Close prime
Low Vent-----------------.046---------------------------.037----------------------------.038
Level Vent ---------------.043---------------------------- * -----------------------------.036
High Vent-----------------.048---------------------------.043----------------------------.037
*I did not time level priming when testing the level vent/pan position.

I began this series of test thinking that the big variable would be the vent location. However, I am now concluding that it is of minor concern compared to the location of the priming powder in the pan. I still like a vent level with the pan flat won't loose sleep over a pan a little high or low.
 
All of the work represented here was based on igniting the powder "artifically" using a red-hot copper wire. This was done intentionally to remove the variables in amount, quality, and location of the sparks. In reality the flint shooter must manage his lock to minimize these variables. Regardless of what the experiments show us, the shooter must place priming powder where his sparks will land. Time with his gun will determine this. However the shooter need not be afraid of priming powder too close to the vent - that is to be encouraged. It is far better to have the prime too close than too far away.
 
-----

The second article called “Pan Vent Experiments – Continued” I concluded with:

Conclusions drawn here are based on these photos and the data collected in the earlier article. A strong argument can be made for the level vent location used by the majority of flint makers. Numerical data supports this, and these photos show a strong flame moving through the vent. My rifles use this location and I see no advantage in changing them.

An equally strong argument can be made for the low vent location. The photo evidence also shows an impressive flame front to go along with good timing numbers. If my rifle had a low vent, I would not change it.
 
I question the location tested here with the vent located .030" higher than the top of the pan. The flame traveling through the vent is noticably less than the the other positions. I timed a high vent position earlier, but I did not specifically set the vent to the 030" position photographed here. Since high vent data gathered earlier was not precisely placed, it may not be valid here. Based on the weak flame seen inside the barrel, I tend to conclude that .030" may be too high for best ignition.

-----

My hope here is not to mislead by looking at a single photo or chart.

Regards,
Pletch