Lyman trade rifle touchole

[Larry Pletcher]

I guess I should get into this discussion since my testing has been mentioned. The whole experiment was called "Pan/Vent Experiments", but was broken into six parts because it was easier for me to deal with. Part 6, however, deals with priming powder covering the vent. (Part 6 is at the link below, but I encourage you to look at the rest of the experiment as well.)

Part 6 - High and Low vent experiments

In the is part I wanted to see if a high or low vent position changed ignition speed. As you can see in the photos, the low vent was near the bottom of the pan. When I banked priming powder against the barrel the prime covered the vent. I did NOT attempt to work prime into the vent however. I timed 15 trials with the prime in this position as well as banked away. I also did a high vent test the same way.

After averaging 15 low vent trials were as follows:
Prime against the barrel and covering the vent --.038 seconds
Priming level in the pan --.037
Priming banked away-----.046
The high vent average when primed against the barrel was .037

There is a short video that shows the methods I used. This will give you a feel for what I went through to insure valid data.

I would also add that in my personal gun, I use a Chambers vent liner and prime against the barrel. I can see fffg barrel powder at the vent opening. My prime almost touches this. It is my opinion that two charges this close together ignite as a single charge.

One last thing I would say after doing this type of timing over 25 years is that human eyes and ears are terrible tools to assess flint ignition.

Regards,
Pletch

 

[Zonie]

Perhaps, sometime when you have nothing to do, you might want to try drilling a 1/16" hole thru the barrel wall to serve as the vent.

Then, try firing it with powder in the vent hole as well as banked up against the side of the barrel in the pan.

All lovers of flintlocks should experience the magic of the Hollywood ClickPOOOOOOOOOFBoom first hand!

 

[Larry Pletcher]

Perhaps, sometime when you have nothing to do, you might want to try drilling a 1/16" hole thru the barrel wall to serve as the vent.

Then, try firing it with powder in the vent hole as well as banked up against the side of the barrel in the pan.

All lovers of flintlocks should experience the magic of the Hollywood ClickPOOOOOOOOOFBoom first hand!

Hey Zonie,
That sounds like my first flintlock- 1/16" hole and no liner.I had two like that. Only thing different was that I didn't fill the vent hole with powder. My only problem was a cheap Spanish lock.

Regards,
Pletch

 

[Grumpa]

I had that experience my first time out for deer...the pooooooff was soooo long that I finally relaxed as I muttered: "What the H***".
Then came the Boom. The ball passed under the deer ( at 90 yards), and it just walked away. :haha:

 

[Albanyco]

Thanks everyone for your input, good reading!

 

[hthomso]

The touch hole on my Lyman GPR .50 is also located slightly to the rear. Has not seemed to have an effect on ignition. I agree with those that say it it ain't, broke don't fix it. :2