flintlock with a vent filled w powder

[Larry Pletcher]

Good evening,
With recent topics about flint ignition, I thought a test we did might be of interest. Many shooters believe that a vent filled with powder causes a slower ignition because the flame must burn through instead of flash through. This is the problem we wanted to test. My gut leans? toward a slowed ignition too, but I wanted numbers to support this.

The link below goes to our testing. Steve Chapman, another member here helped me.

BPM - Filled Vent Test

Regards,
Pletch

 

[tenngun]

interesting. I prick the vent at priming more to make sure its clear. I have never found things like 4f to be of use, though over priming can be noticeable.

 

[Brad McCaffree]

How are earth did Glass and the boys survive with out modern day technology?
Tenngun, how come you're a day ahead of me?

 

[Zonie]

Thank you for testing this.

The results of your experiment does answer the question about the possibility of the prime acting as a slow burning fuse but it still leaves me wondering, why have I occasionally had, on one of flintlocks I owned years ago, which had a small vent hole drilled completely thru the barrel wall, a definite pause with a "foooof" sound after the quick "POOF" of the pan priming but before the main powder load fired?

Of course, I wasn't timing the length of the "foooof" but it seemed to take at least 1/4 to 1/2 second.

Maybe it was because the priming powder I used in the pan wasn't Null B. It was the same 3Fg, DuPont powder I used for the main powder charge. :hmm:

 

[Larry Pletcher]

I trust you guys noticed that I did not give a firm conclusion in the testing. The slowest and the fastest times came from the filled vent tests. It is fair to say that the differences within a group is larger than the differences between groups.

To an experimenter, this is very frustrating. It leaves one with the feeling that you haven't been successful in the testing.

I'm left with one of two explanations. Either:
1. There is an unknown variable that has a larger effect than the variable I tried to measure. As the experimenter, I have failed to isolate or at least control the larger variable.

or

2. There is no statistical difference in the two groups.

The problem is that I don't know which is right.
Regards,
Pletch

 

[Don Steele]

Thanks Pletch. I always enjoy reading the experiments you have conducted to address some of the things folks think they know. Unfortunately, there are so many variables involved in the firing process of a flintlock/blackpowder system that there's often inconsistencies in the results.
I believe that using an actual powder charge in the barrel is introducing uncontrollable variables and thereby clouding the results.
If we know how much heat is required to set off a main charge,(Do we know that, or is that a whole new set of tests that need to be run..???) we might consider removing the powder from the barrel and replacing it with a heat sensor that only triggers when that level of energy reaches it. With that setup, we're only measuring the efficiency of the energy delivery to the "main charge zone" inside the barrel.That's really the core question. Take the main powder charge out of the test protocol, and we've removed all the variables such as fouling, effects of packing density of the main charge, even simple differences in each charge of powder, etc.
All good stuff to ponder..!! :hatsoff:
Thanks Again.

 

[Vaino]

Although your tests were inconclusive, they do give credence to the fact that there's no appreciable difference w/ a clear vent and a "fuse" effect w/ the vent filled w/ powder.

Seeing the 1/16 dia TH was .210 long, which to me is a long vent, the difference w/ a vent that long VS a vent in a White Lightning" liner would be even smaller.

When I built my first flintlock LR for squirrels, I sat down and really thought about spark production and direction, TH location in relation to the plug face, the specs of my homade TH liner and the prime type, amount and location in the pan.

Well...after a trip to the range for sight in and careful attention to the priming factors, I was very pleased w/ the results.

But then I went squirrel hunting and "in the heat of the battle", so to speak, the hurried loading and my indiscriminate priming yielded the same results as when at the range w/ it's attention to details. Also....have never used a vent pick....in fact, don't own one.

Were my thoughts about ignition responsible for the reliable performance of this LR? Possibly....but evidently luck played a large part.

This specific test, although inconclusive was worthwhile....it eliminated a factor that some would blame for slow or erratic ignition. Thanks.....Fred

 

[earlwb]

Those are great results. Very fascinating too. Thanks for performing these tests.

I would try to see what happens if the flash plan is full, partially full too. A lot of guys, especially the newcomer, tend to over fill the flash pan. Thus a flash pan filled so that it covers the vent might be the problem. I have seen a full flash pan go off when ignited, but it doesn't fire the main charge. Or you get a weird hang fire because of it too.

 

[uno676]

Nice experiment very informative.

 

[Vaino]

My priming horn throws variable amounts of prime which at times are excessive and are swiped w/ my finger so the frizzen will close completely. Have found that the amount and location of the prime in the pan hasn't changed the ignition times...half full, 1/3rd full or full full and if the prime is at one end of the pan or some other location.

The flintlock LR that I mentioned seems to be how the flintlock LRs of yore probably functioned....reliably, w/o a whole lot of fussin'.

When starting a hunt, one thing is for certain......a sharp flint which dulls to some extent but always supplies plenty of sparks.

A lot of the problems encountered stem from lousy locks and breech types that are too complicated.....including THs that are faulty and feed complicated type breeches.

Perhaps I'm lucky to have a flintlock LR that is no more complicated than a caplock and is as simple in operation.....Fred

 

[Larry Pletcher]

Friends, I appreciate your thinking. THis kind of stuff is kind of fun.

Fred, your comments about spark production reminded me of a conversation with Gary Brumfield. He described how he gets ready for opening day. Starting with a new sharp flint, he knapps it heavily making a very jagged edge. Then he snaps the lock a couple of times to take the longest points off, still leaving a rough edge with many sharp points. Very reliable, he said.
Regards,
Pletch

 

[Onojutta]

You also did a test on your website where you showed that a vent hole placed lower than the top of the pan showed better flame getting to the barrel than the common "rising sun" configuration. This test seems to complement that test, since a lower hole that is covered by the priming powder is probably not much different than the "filled" vent. What do you think?

 

[Larry Pletcher]

You also did a test on your website where you showed that a vent hole placed lower than the top of the pan showed better flame getting to the barrel than the common "rising sun" configuration. This test seems to complement that test, since a lower hole that is covered by the priming powder is probably not much different than the "filled" vent. What do you think?

I like your idea. The test you mentioned used a low vent with priming against the barrel. In one set of trials the prime covered the vent although the vent itself was left clear. Looking at the recent test with a filled vent and the test you mentioned, neither had a negative statistical effect on the ignition times. In fact the low vent test was one of the faster averages.

I believe that looking at data in multiple tests to solve a problem, I think, is reasonable. However, drawing conclusions could be sketchy. Before doing that let's make sure of a couple of things.

The flash channel is short - as in a vent liner.
The vent is squeaky clean of fouling.

Now for the sketchy part. My gut says that the closer the prime is to the barrel charge, the faster the ignition. I like fffg peaking out of the vent liner. I like priming powder against the bottom of the vent liner or as close as I can get it. I don't care if the vent is low, covered, or if prime gets into the vent liner. (In fact I don't care much about the vent location as long as it isn't too high.) I like a coating of prime covering the complete pan for the sparks to land in.

This probably sounds pretty far from loading from the pouch, priming from the horn, slapping the lock to level the prime, and firing. If you think about it maybe it's not so far off after all.

This is one guys opinion drawn from probably too much time with a computer interface, a hand full of photo cells, and a really good Siler test lock. This and 50 cents used to buy you a Coke.

Regards,
Pletch

 

[Zonie]

If I were to pick on any part of your test it is that you used Null B to prime with.

Almost no one uses Null B and although some use 4F powder, I think most (including me) use 3Fg or even 2Fg for the prime in the pan.

These larger, slower to ignite powders may show more of a difference in the speed of a filled, straight drilled, deep vent hole.

 

[Larry Pletcher]

Jim,
Just for fun we video taped varying powder sizes in slow motion. We have Siler with Null B , 4fg, 3fg, 2fg, fg, and Cannon grade. The cannon grade had particles so large that we needed to move them manually to close the frizzen. At 5000 frames/second, was really fun. BTW the Goex Cannon was faster than the substitute powder we timed. Actually the sub could be timed with a calendar.

Regards,
Pletch

 

[Zonie]

Your talking about using a calendar reminded me of an old guy at the shooting range.

He was a good friend, long deceased, who just liked to hang out at the range so one day, when I was trying out my .36 caliber flintlock I had just finished building I said to him, "Have you ever shot a flintlock?"

He said he hadn't shot one in his entire life so I said, "It's about time we change that. Let me load this up for you and you can shoot it."

After giving him a few instructions on the set triggers and what to expect, I loading it and handed it to him with it at half-cock.

He cocked the gun, took aim and pulled the trigger.

It quickly fired and he handed it back to me with a big grin.
I suggested that he should fire it again so I loaded it up and handed it back to him.

After 4 more shots had been fired, all of them going off in thousandths of a second after he pulled the trigger, we pulled the target and his group was maybe a 2-3 inch size.
He was pleased as punch.

Next week, I was back at the range with a few other guns I had built.

He was standing with a few other guys and pointing at me he said,
"See that guy with them longrifles?
Last week he let me shoot one of his flintlocks.

I could'a rolled a cigarette and lit it before that damn thing would go off." followed by a wink and a grin at me. :rotf:

 

[M. De Land]

That is precisely the edge that pressure flaking with a good copper or horse shoe nail tool will give regularly Larry,much more consistently than will be produced by hammering on the flint face which tends to fracture and prematurely wear it out.

 

[hanshi]

From your results, Pletch, I'm willing to surmise that there would be no statistical difference in your averages for both. I like to hit the opposite side of lock panel and get a few kernels of 3F to roll into the pan prior to priming. Never had a hangfire when I do this. In fact I have only one rifle that gives occasional hangfires, a .32 with a Chambers late Ketland lock. The vent is 1/16" but I think putting a pick in the vent before priming is going to stop hangfires.

 

[Tom Compton]

I usually agree with you Zonie but not on this one. I'm reminded of an interview at a school. One kid said "everybody" used drugs and another said "no one" used drugs.

I don't know any flint shooters priming w FFg or FFFg. Most use 4F. I use 4F but just got some Null B. Top shooters buy top quality locks, tune and polish them, use flints right for the lock, open and cone (in side, outsid or both) touchholes. Why use a measurably slower priming powder?

IMO .003 seconds here .005 there etc and soon scores and hits are up.
TC

 

[tenngun]

I do THINK that although we can do some tricks to get the fastest ignition from a flinter, that at very best there will be an irregularity from shot to shot. Careful loading under the very best conditions may produce closer to regular predictable times. However that goes out the window when you get a little soot on your frizzen you hadn't wiped off, a bit of a breeze, high or low humidity or ambient temp. Nor forget the angel with the weak bladder. You have to do follow through. Each time you touch off a shot you have to think' hang fire'.