touch hole in "tub drain position" example

[WadePatton]

thanks so much Pletch for taking the time to do the testing and then also to come here and try to keep us (me) from dumbing it up.

i had breezed through your testing at some time in the past, but failed to lock in on touch hole position issue.

now i take away: banking away is to be avoided always. low is preferred to high-but sunrise will do.

i surmise a "new" position for my flash paths: crack of dawn or first light.

[Larry Pletcher]

snipped. . . . .
now i take away: banking away is to be avoided always. low is preferred to high-but sunrise will do.

i surmise a "new" position for my flash paths: crack of dawn or first light.

Wade,
I guess you pretty well hit it.  The last test showed me that a vent can be too high, however I'd stay from extreemes anyway.  Low doesn't bother me.  I will still make my vents level with the top of the pan - probably no higher. My reason is that if I ever want to sell the gun, a low vent might be questioned, as someone mentioned earlier.The idea that a low vent will be slow is going to be around for a long time. If I had a gun with a low vent I'd be unlikely to change it.
Regards,
Pletch

[gunsports]

One other thing to consider is the person who may be standing to the right of you when you fire. If you look at high speed photography of a flint gun firing, you will notice a jet of flame exiting the flash hole. This jet is not the prime igniting, but gas from the main charge igniting and escaping from the flash hole.

I was nearly blinded by a flint lock that was fired about 2 feet to my immediate left. On examination, it was found that the flash hole was positioned slightly above the top of the pan. Had I not been wearing safety glasses, I would have lost my sight. I still have powder burned into my skin.

That is why; on the guns I build, I position the flash hole midway between the top and bottom of the pan. Now the far side of the pan acts as ramp directing most of the combustion gas up and away from anyone who may be standing immediately to the right of the shooter.

I gave found no adverse ignition problems from this vent position.

Yes, I know one should not stand immediately right of a flint gun being fired. In this instance I was tutoring and the shot was not supposed to be fired before I had not stood back. But, accidents happen.

Also, you will see on old guns; especiallu those used in massed volley fire, that a guard was often placed to the right of the pan; I believe specifically to adress this problem.

Rather be safe than sorry; especially in this lawsuite mad world of ours.

[2longhunt]

I hate to comment on this subject a month after the last post but I have found this subject very interesting and informing. I'd like to show everyone a couple pictures of a couple guns I have. (I do this reluctantly). 

The first one is a smoothbore that I received "in the white". I have not fired this gun yet but according to what I have just read, I can expect possibly poor ignition results due to it being drilled too high. It's hole is a little bit towards the rear of the pan and after probing with a drill bit, it seems to bump the end of the breach plug.



The second, well, try not to laugh too hard, was a rifle I built back in 1996 from TOTW parts. It's their 1770 Bivins rifle. I had a gunmaking mentor help me along the way in certain areas. One night, while at his house, he was going to drill and install a touch hole liner. He got to talking and didn't quite pay attention to what he was doing and drilled the hole too far forward. Well, I eventually got to fire the gun and the results were not good. It consistantly did not fire and had a lot of flashes in the pan.

I took the gun back to him and he removed the insert, filled it and then redrilled the hole again. Well, he again was jabbering away and, low and behold, drilled the hole too far to the rear this time. He put a new insert in and I took it home to test fire. The results were about the same as the first time! 

I took the gun back and left it with him to see if he could fix it when no one was there for him to talk to. He took it to the range to test fire. He ended up using a very small pointed file and angled the hole a little towards the pan. Well, this did seem to help the ignition but I would say that I still only can get it to fire maybe 4 out of 5 times without a flash in the pan.


I've always been embarrassed to show people the rifle because of how it looks but have learned to live with the results. I really did not see it being safe to remove the second liner, fill and try inserting a third.

So, I guess I have a question about touch hole placement fore and aft. Does it matter much? I seem to have my guns touch holes sitting too high but didn't know if the fore and aft would hurt. Apparently it does on the rifle.

Thanks a lot.

Mark

[54Bucks]

I hate to comment on this subject a month after the last post but I have found this subject very interesting and informing. I'd like to show everyone a couple pictures of a couple guns I have. (I do this reluctantly). 

The first one is a smoothbore that I received "in the white". I have not fired this gun yet but according to what I have just read, I can expect possibly poor ignition results due to it being drilled too high. It's hole is a little bit towards the rear of the pan and after probing with a drill bit, it seems to bump the end of the breach plug.



The second, well, try not to laugh too hard, was a rifle I built back in 1996 from TOTW parts. It's their 1770 Bivins rifle. I had a gunmaking mentor help me along the way in certain areas. One night, while at his house, he was going to drill and install a touch hole liner. He got to talking and didn't quite pay attention to what he was doing and drilled the hole too far forward. Well, I eventually got to fire the gun and the results were not good. It consistantly did not fire and had a lot of flashes in the pan.

I took the gun back to him and he removed the insert, filled it and then redrilled the hole again. Well, he again was jabbering away and, low and behold, drilled the hole too far to the rear this time. He put a new insert in and I took it home to test fire. The results were about the same as the first time! 

I took the gun back and left it with him to see if he could fix it when no one was there for him to talk to. He took it to the range to test fire. He ended up using a very small pointed file and angled the hole a little towards the pan. Well, this did seem to help the ignition but I would say that I still only can get it to fire maybe 4 out of 5 times without a flash in the pan.


I've always been embarrassed to show people the rifle because of how it looks but have learned to live with the results. I really did not see it being safe to remove the second liner, fill and try inserting a third.

So, I guess I have a question about touch hole placement fore and aft. Does it matter much? I seem to have my guns touch holes sitting too high but didn't know if the fore and aft would hurt. Apparently it does on the rifle.

Thanks a lot.

 For what it's worth...... I think the whole key is to have pan powder as close to the main charge as possible. When the location of the pan to vent is good and the vent is coned, the pan powder nearly mixes with the main charge. Giving the fire from the pan powder the best chance to ignite the main charge. I never could understand why anyone would want to pic away any powder in the main charge or block the vent with a pick when loading their gun. Always seemed to me that powder burns....... but not air.
 I would think in your case the bottom of your frizzen actually creates a void in the pan powder nearest the vent, that does no help given the vent location. If it were mine and causing me problems I would start by removing the frizzen and making the bottom which functions as the pan cover flat. At least towards the vent. I'de probably also cone the outside of the touchole a little. Then try it with a full pan banked towards the touch hole.

[whetrock]

Just to echo the last comment, here's a photo of the bottom of a new frizzen on a Davis English lock. You could easily grind down the frizzen on your current lock so that it more or less matched this one. (Just keep it cool, so as not to damage the temper.) (Here's the photo, but keep reading below.) Also, if you go this route, ditto on the “full pan” comment. Don’t want to insult anyone here, but need to mention that sometimes just using more powder makes a world of difference. Fill it up. (Don’t make the spark have to look for it. And remember that more fire means more chance of ignition.)



But that said, I really think I would just go for new inserts on both of these. The first one you showed being too high and back (but not yet having an insert) is a fairly easy fix. The smith would just enlarge the current touch hole forward and downward, and then use the enlarged (and thus appropriately centered) hole as the pilot when drilling for the insert.

On the double lined situation, I would recommend pulling out the new insert, fill the hole with solid steel, then redrill the touch hole where it belongs in the newly installed steel core. It only needs to move forward and down 1-2 mm, and so the new hole would still be in the new insert. (Just take care that the new hole and any coning stay out of the threads.)

If you used plain steel, rather than stainless or an alloy, then the fact that the new hole was off center (of the insert) would barely show anyway. Stainless would be fine and certainly durable if you don’t mind the new hole being visibly off to the right. (I would think that even if it is visibly off center, that would still be much better than poor ignition.) The new hole could be coned from the inside, if you want. Or it could be left straight. I would really expect a correctly positioned straight (not coned) touch hole would work better than a badly positioned coned insert.

(A third option, but one I couldn’t recommend, would be to drill out both current inserts and put in one large one. But I’d be really reluctant to do that, as I'd really be reluctant to do anything that would "further offend the integrity” of the barrel. I really would try to avoid cutting away any more of the barrel.  I just mention this third option here for the purpose of bring it up for discussion. Maybe others have an opinion about this third option?)

[whetrock]

Okay, the teacher in me has to say it...

I do hope everyone realizes that this double, overlapping insert situation is dangerous.  A much better, much safer way to have dealt with the original missplacement would have been to pull out the misplaced #1, use files to slightly enlarge the hole down and to the left so as to be able to put good steel (not threads) where the touchhole needed to be, drill the shifted hole round, tap it and then plug the hole with solid steel, then redrill a straight touchhole where it belonged. The new touchhole would have been off-center of the steel plug through which it passed, but it would have been a perfectly safe solution.

Let me also mention that drills will wander, esp if the point is not dead center on the drill rod and the cutting edges are not equal. For that reason, if drilling a hole for a touchhole insert, I've found it helpful to put a small pilot hole in at the point where I want the final touch hole to be, and then take a marker and draw on the position of the final hole in relation to the pilot. I then increase the size of the hole in size in steps (rather than just jumping from small pilot hole to full size hole to be threaded). That way, if it wanders at all, you can adjust the position before you get to the final size of the hole to be tapped. (Having a circle drawn on the flat where the final hole should sit helps you be sure the pilot holes stay centered where they are supposed to as you move up in sizes.)

[Flint62Smoothie]

The smith would just enlarge the current touch hole forward and downward, and then use the enlarged (and thus appropriately centered) hole as the pilot when drilling for the insert.

Let me also mention that drills will wander, esp if the point is not dead center on the drill rod and the cutting edges are not equal. For that reason, if drilling a hole for a touchhole insert, I've found it helpful to put a small pilot hole in at the point where I want the final touch hole to be, and then take a marker and draw on the position of the final hole in relation to the pilot. I then increase the size of the hole in size in steps (rather than just jumping from small pilot hole to full size hole to be threaded).

FWIW when I encountered a flint drilled TH that needed to be 'moved', I used a small 4-flute end mill to make the first hole in the correct position.

IMHO This is a far superior method than drilling ...

[Muggsy1776]

When I got my Charleville (Japanese) many, many years ago it came with the hole half hidden by the pan.  It was my first flintlock and I never thought much about it other than I had a miserable time shooting it- constant ignition problems.  I used it for reenacting, but it wasn't until I started live firing it that the pressure out of the hole created a groove in the pan.  Now I have a completely open hole and almost zero ignition problems.   I always racked it up to the poor quality of construction.

[Roger Fisher]

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.  

This very subject came up on a w walk just yesterday.  When I suggested this concept while jibber Jabbering most of the boys looked at me as if I were nuts since I get that look often (home in particular) I left it slide.