Priming powder location in the pan

[Larry Pletcher]

I'm getting ready to run some experiments on the location of the vent in relationship to the pan. It was suggested to me that I try the following experiment to see what happens when the priming charge is located differently in the pan.

Here are pics that show the effect of powder location in the pan. First, the top pic shows how the experiment was done. I placed an index card between the pan and the barrel stub. I primed with a measured amount of Swiss Null B. My plunger type pan charger threw 1.6 gr, but I weighed the charges and included only those whose weights were within 1 tenth gr. The charge was ignited with a red-hot copper wire. The first pic shows burn pattern in a pan with the charge as far from the vent as possible. The second shows the pattern with the charge in the center of the pan. The last pic shows the results with the pan charge as close to the barrel as possible.

(Fixture with index card in place)

(Priming powder on outside edge of pan)

(Prime in center of the pan)

(Prime as close to barrel as possible)

This test was not designed to predict what happens in the vent or the barrel. It simply shows the relative amount of fire hitting the side of the barrel. (This is an easy test to do. Since I tried only one type of powder and used only one lock plate, You might be interested in trying this with your lock plate.)

Regards,
Larry Pletcher
Pletch

 

[roundball]

LP, you are a very generous man to share so many rare insights to us as a result of your personal time and expense...those are outstanding and very revealing stills.

Looks like the closer the powder is to the vent the smaller the spread is, but the more intense it is...for years I've followed the suggestion of banking the powder away from the vent to get a flare off the slope towards the vent and never even challenged it...but it's clear it's the lowest intensity of all of them...think I'll experiment with my prime location at the range this year.

And given the coverage of the spread it seems that vent hole position relative to the center of the pan might not be nearly as critical as I've always heard that it was...you can see it's dense all the way back to the fence.

More excellent work my man, and thank you very much for sharing it with us!
:hatsoff: :bow:

 

[armymedic.2]

hmmmm....i agree with roundball. i bank to the far side cause "im s'posed to" --however, due to rushed shots in the feld, my powder does end up in different places in the pan on quick reloads- i have never seen a difference in ignition, except when the powder is right up against the barrel. sometimes though not all, it is slower. i beleive it is because the powder right up against the barrel, puts it right next to the vent as well, which can lead to powder geting in the liner, and creating a fuse. i know this has happened because it is very obvious when the rifle goes....psssssssssst.....boom. so, in otherwords, i woud beleive that ignition is faster/better when close, as long as some does not get flipped into the liner. having said that, i hate fuses and would prefer to keep powder at far edge as i know it will not fuse.

very interesting experiment, if i was a paper shooter i just might start to plug the vent with a feather, put the powder by the barrel, and then punch my hole (right after removing feather of course) seemingly getting faster/.better concentrated ignition. all really cool. i wonder if the frizzen bottom and the flint itself being above will cause it to flash differently? thanks for your donation of time!

 

[Tom Gauldin]

Pletch,

Great experiment !!! :hatsoff:

Looks like we should keep the powder close to the touch hole.......

You measured the charge very carefully. I usually just dump it in till the pan is level, and, in effect, covers all areas of your experiment.

It is great to see someone who is willing to spend the time on testing.

 

[paulvallandigham]

Is that one of those bottle neck pans, Larry? Its difficult to see if the bottom of the wider portion of the pan is deeper than the neck portion is.

 

[roundball]

"...i wonder if the frizzen bottom and the flint itself being above will cause it to flash differently?

Excellent thinking...the bottom of the frizzen would definitely kick the spread backwards, concentrating it even more around the vent...so that thinnest looking spread from the outermost powder position would be more dense around the vent.

However, I don't believe the flint would have much influence on the spread as it relates to the vent hole itself...at least with mine, the edge of the flint is just above the vent hole when all the way forward.

 

[Many Klatch]

I've always filled the pan with powder and then some. I figure if a little powder is good then more would be better. Did you try it with the pan level full?

Many Klatch

 

[Sherlock]

I would read the cards as the opposite conclusion. The explosion nearest the touchhole, for example, is most concentrated and expands as it travels outward(away) and upward. That outward bound focused explosion energy doesn't necessarily fire a spark into the touchhole which is a tunnel leading in the opposite direction. I have just seen too many guns give better ignition with the powder tossed outward in the pan. Additionally we all know that every gun likes a different pan charge. What kind and how much is important for dang sure! And lastly, you know that Fred Stutzenberger did that electronic timing testing of ignition years ago and found that crushed down priming was in fact the fastest for pan ignition, with the pan priming held constant side to side(level just at hole level). That's caused me to use crushdown, always, then figure out amount to toss outward in the pan. Hmmm? Wonky

 

[Mulebrain]

Great info here! I am a Hoosier too!

According to Bob's Black Powder Notebook!

How do I prime for best performance?
Once the flint has struck the frizzen and sparks have fallen into the priming powder, there is a flash as the powder burns. Best performance will come from having that flash be as fast as possible. Any powder can be used as priming powder. It is well known, however, that finer grained powders burns more quickly, so it is advisable to use them. For me, priming powder is always FFFFg (4F), never anything else. A common mistake made by beginning shooters is to put too much priming powder in the pan, the feeling being that a big flash will work best. Not so. A big pile of powder may well block the touch-hole, and then the fire train must burn through that pile to reach the main charge. It's much better, much faster, to have only the flash ignite the main charge, not a slower burning trail of powder. On most pans, one third of a pan of priming powder, or less, will work best. Well set up and properly primed, a flintlock will fire reliably while being held upside down. Strange, but true. The 'air burst' of burning prime flashes through the touch-hole with no trouble.

Here is a link to his very informative sight!
[url] http://home.insightbb.com/~bspen[/url]/

 

[roundball]

I'm not debating just trying to think these points thrugh out loud...

While I agree that the closest powder/vent relationship must surely send flare away from the vent of course, I still get drawn to the intensity comparisons.

The closest relationship has a very intense, dense saturation all over the breech/vent area, while the one farthest away had only a light, thinly sprinkled intensity.

 

[Mulebrain]

I wanna see this experiment with the lock complete with frizzen and flint sparking that charge!

 

[Harddog]

That outward bound focused explosion energy doesn't necessarily fire a spark into the touchhole which is a tunnel leading in the opposite direction.

GW,

Are you sure that a spark must enter the vent hole to acheive ignition of the main charge or is just the heat of the pan powder burning more likely what ignites the main charge?

Randy Hedden

 

[Mulebrain]

Wicked ffg prime going off!
[url] http://www.youtube.com/watch?v=GzgVnH6uEP0[/url]

 

[Leonredbeard]

Harddog,
Heat, in the form of an intense needle of glowing hot gasses enter the flash hole and light the charge. Now you can have a actual fine piece of glowing steel having been struck off the frizzen enter the flash hole with and empty pan and fire the charge. But that would be unlikely to happen with any amount of prime in the pan.
volatpluvia

 

[bob4st]

...that's one of the coolest experiments I've seen in a long time!!... Thanks!!
Bob

 

[Sherlock]

Go read up on explosive theory, especially shaped charges: shaped charge mechanics is what we are talking about here. You need not go deeply , a shorter explanation will do as from wiki. My own theory, not fanatical belief, is that steel shavings(sparks) come off that frizzen, and are hot enough to ignite what I have determined by observation to be my best pan charge for ignition for this gun. That charge of crushdown, has NO GLAZING(graphite coating), as I have crushed it (I only have used DuPont or Goex), and the fineness is from less than the fffg I started with to near talcum powder-like. With the charge biased in position from the outside of the pan toward the bottom of the pan under the flashhole, the sparks hit it like the electrically fired sequential charges in a strip mine to some extent, and the pan explosion travels from the outer pan to the inner, the length of the pan , or wherever it lights off, blasting fines, chunks, and various burning, burnt, and unburnt particles toward the touch hole, BECAUSE OF THE SHAPE OF THE PAN, AND A BIT OF RESTRICTION FROM THE FLINT, LOWER COCK JAW, AND FRIZZEN BOTTOM, direct the flash to the touchhole like a shaped explosive charge in a weapon is directed. Particles and heat energy penetrate the flash tunnel, long or short and the gun charge lights off. PHEW!!! Not as neat as a cap for sure, and every dang gun different too, in ignition requirements, except for aged wisdom: tip that pan powder outward before pulling the trigger. That's my theory and I reserve the right to change my mind anytime I think better. Wonky

 

[Larry Pletcher]

Thank you for all your thoughts and comments.

Roundball, Since I retired from teaching this is the way I get my jollies. I used to think that teaching was more fun than learning. Now I think the most fun is learning.

Paul,
The lock is an L&R late English - the one with the waterproof pan. The pan cavity tapers toward the vent in overall shape. The depth is the same .13" from the vent out to about 1/2 way then curves gently up to the rim at the opposite end. I have a couple of Siler locks with varing pan shapes. It would be interesting to try them too.

Mulebrain, glad to hear from another Hoosier. I believe that a complete lock would be worth trying. In most cases I think the frizzen will be out of the way. In the high speed photograpgy, if the frizzen returned, it did so before the ignition took place. In the fastest, Manton, the frizzen returned just as the Manton's pan caught. In the rest the frizzen was moving away again before the pan ignited.

BTW on the Chambers Roundface lock we did at Friendship, the frizzen returned and stayed over the pan and actually helped confine the ignition vertically. Jim joked that He worked very hard to get the frizzen to do that.

GW, I expect that the timing that you mentioned with Fred Stutzenberger was a MB article that Fred and I collaborated on in Feb, 2000. He did all the machining and I did the timing. We worked together on an earlier article in which he did the writing and I supplied the data. I don't remember the date for that one.

Someone mentioned that the burn pattern was dense enough that height of the vent may not be as big an issue as we had thought. I'm undecided on this, because we can't tell which of the burn marks occured first. And, vent height is the main reason I started this, and I don't want to forget why I started. It would be so easy to get off on a side experiment and forget my goal to study vent height.

Thanks all for your thoughts,
Regards,
Pletch

 

[roundball]

That outward bound focused explosion energy doesn't necessarily fire a spark into the touchhole which is a tunnel leading in the opposite direction.

GW,

Are you sure that a spark must enter the vent hole to acheive ignition of the main charge or is just the heat of the pan powder burning more likely what ignites the main charge?

Randy Hedden

Just the heat from the flash will do it

 

[Vaino]

Thanks for the pics but one question....the separate "dots" on the cardboard are from burning powder granules but how are they pertinent if radiant heat entering the TH normally ignites the charge? In years past, I take it that the flintlock was considered a reliable firearm and in the heat of battle little care was taken as to priming charge location and even w/ just a drilled TH, again I imagine that the rifles "went off"? Judging from all the posts asre failed ignition, it doesn't seem we've progressed w/ the "modern flintlocks" at all and I really can't see how a battle could be won w/ the flintlocks of today. Where did we go wrong? Please excuse this slightly off-topic post and your experiments are very interesting....Fred

 

[Sherlock]

Thanks to Pletch for the chance to theorize and everyone for their considered views. For me,if a lock works reasonably its hard to figure out what is better. It's the failure analysis that's easier and make one improve a lock geometry or priming practices or the mechanics of what you have. Manufacturers have led the way and experimenters too.Pletch's experiment simlated a flash in the pan and that's the first half of getting a PRB to come flying out of the muzzle. I believe that both the ignition products of that flash and heat energy sufficient to ignite the barrel charge are blown through the flashhole. Everyone has noted the dramatic difference that opening up a touchhole sometimes gives to lighting off a charge, or the speed of the total process improving when you don't put 2f in the pan, but rather 4f. BTW, my view is that "chunks" of ignition process flying down the pan are in a race with radiant energy to get to the barrel charge and ignite it. Don't need much for good powder ignition and guns producing better radiant energy projection are the FAST ones. Wonky