Flash size & ignition

The other night, I was cleaning some stuff up in the garage & distracted myself with some experimentation. I have a Pedersoli Kentucky flintlock that has had poor ignition & made me convert it to percussion to get it sighted in. So I set about to shorten the flints & run some tests to see if I could get better ignition with it. After shortening the flints so that the flint wouldn't rest against the frizzen in half cock, I started playing around with powders. Mind you, I'm just holding the lock with welding gloves -- it's not attached to the rifle. The Scheutzen 3F powder failed the first time but went off 8/10 times. The flash was small and the little fireball was about 1-2" in diameter. Then I tried my homebrew, which is fast but very low density & irregular sizes. It went off 10/10 times and the fireball was consistently about 3-4" in diameter.

I won't be able to make it to the range for a while yet. So I'm curious if others have noticed any difference in the speed & reliability of ignition relative to the size of the flash in the pan. Does that bigger fireball mean faster & more reliable ignition? Or does it just mean more flash in the face?

I have the Scout Rifle in 50 cal as a flintlock. It uses the exact same lock as your Kentucky rifle. It's just a 28 inch barrel instead of 35. I have Scheutzen 2f. I ground my 2f using a hand operated pepper grinder to 4f. Every time I pulled the trigger thus far as long as the flint was sharp and there was enough 4f in the pan it fired fine. 3f should work but 4f is very fine and can tap the rifle on the side and let some 4f inside the vent hole helping ignition. I don't do that. Flintlock is a learning process. I have an Investarm with a L&R lock. The L&R lock is great but the pan is very deep and requires 3 to 5 grains of powder or so to go off. It's a learning process.

Well, I did some simple ignition tests. Homebrew in the pan & commercial down the bore gave reliable ignition 11/11 times. Fast & consistent too. Might yet use that rifle with the flintlock.

Flintlock is a bit more involved. It's basically a mechanical match strike. You have probably used one of those old fashioned phosphate wood matches where you strike the grey strip on the box. The flint is the match and the frizzen is the gray strip. The flint or match in this case can be used many times. You do need to have it Knapp with leather and the flint must be sharp. Eventually you will need a new flint just like how if you want to use a match to strike fire you may need a new match if the old match is not working. Cannot forget pan powder and making sure that the vent hole is clear. I am glad you got your rifle working better. The Kentucky Flintlock Action they made is a decent lock. Probably the best production lock compared to Traditions or Investarm flintlock locks.

Did about 15 yrs of competition shooting off and on between 1972 to 1988. Was using Siler flintlocks back then. To get consistent ignition , simply always used about 7GR. of FFFFG in the pan , brush the lock surfaces clean , pick , and prime the pan. Then for consistency , and since I'm right handed ,I would , close the pan , tilt the longrifle to the left , and bump the stock with palm of the hand , so the powder in the pan would go down the touch hole . It sounds like a minor thing , but it works for me. I seldom have a failure to fire , even today. There are four or more flint lock manufacturer's around , and all have fine locks for custom guns. A good lock , good flints , and good technique , make for good ignition...........oldwood

Too big of a flash means you have too much powder in the pan and will actually delay ignition.

Too little pan powder it won't ignite. I have had both happen to me.

Nuthatch said:

The other night, I was cleaning some stuff up in the garage & distracted myself with some experimentation. I have a Pedersoli Kentucky flintlock that has had poor ignition & made me convert it to percussion to get it sighted in. So I set about to shorten the flints & run some tests to see if I could get better ignition with it. After shortening the flints so that the flint wouldn't rest against the frizzen in half cock, I started playing around with powders. Mind you, I'm just holding the lock with welding gloves -- it's not attached to the rifle. The Scheutzen 3F powder failed the first time but went off 8/10 times. The flash was small and the little fireball was about 1-2" in diameter. Then I tried my homebrew, which is fast but very low density & irregular sizes. It went off 10/10 times and the fireball was consistently about 3-4" in diameter.

I won't be able to make it to the range for a while yet. So I'm curious if others have noticed any difference in the speed & reliability of ignition relative to the size of the flash in the pan. Does that bigger fireball mean faster & more reliable ignition? Or does it just mean more flash in the face?

Click to expand...

I've always felt that where the spark shower lands in the pan is as important as how much of it is generated. Apparently the color of the spark shower is important as well as some are hotter than others. If the sparks hit the powder in the pan directly and don't have to ricochet around a bit first loosing heat , they would be better at powder ignition as well.

One would have to do some high speed video of it to really see.
A day of hard science would be worth more then a thousand opinions.
Some rules flint shooters seem to agree on. Pan powder is best lower then the touch hole.
The touch hole needs be clear, so there is not a train of powder to ‘fuse’
So a healthy dose of “I THINKS’.
As that top layer of flash powder starts to burn hot gas expands in to the vent, and ignition of the charge can start even as the last of the prime is ignited. Any mushroom cloud above your pan is for nought
Above the fellow said seven grains worked for him. A balance has to be struck between too little and the sparks not hitting the powder and too much and you getting a fuse.

The pan flash study , was done some years ago , by a guy for Muzzleblasts magazine. It's a well done bit of high speed photography , quite a while before M/B magazine became a slick paper color photo book w/little good info in it. I'm not a member of the NMLRA any longer , so can't access any past info.

I shoot my Kiblers a lot. They are well designed and precisely made of appropriate materials. The flints last until they are too short to knap, 100 shots?? They throw bunches of sparks. I prime with 4F, only because I have some. The volume of prime is only enough to coat the pan, not fill it. The liner brings visible grains of the main charge right next to pan peeking out the flash hole. The heat of the flash, not the direct fire it what sets it off. With a set up like that it is almost cheating. I would bet it would fire often with out prime. The point is the flintlocks can be very reliable.

One you have experienced the difference between an exceptional lock and the rest you are spoiled. If you are fooling around to make it reliable there are issues that need addressing. It could involve tuning or more. I started with a first gen TC flintlock. It was a miserable piece of junk. All the others have been somewhere in between the TC and the Kiblers.

I had a Pedersoli Hatfield. The flash hole was too small. The extra long breech plug was a problem. I got an RPL lock for it. I also opened up the plug chamber and flash hole. It then worked like a champ. After, I fussed with the original lock and made it work just as well as the RPL.

Sounds like the OP's lock lights the prime OK. The first thing I would do is open up the flash hole to 1/16". Then possibly open up the powder chamber in the plug. IF the lock does not spark well, find out why and fix it. Shortening flints?? Perhaps the sear nose is too short and the the half cock is to far foreword? I think that was one issue I addressed, I made a new sear.

Good luck.

Scota@4570 said:

I shoot my Kiblers a lot. They are well designed and precisely made of appropriate materials. The flints last until they are too short to knap, 100 shots?? They throw bunches of sparks. I prime with 4F, only because I have some. The volume of prime is only enough to coat the pan, not fill it. The liner brings visible grains of the main charge right next to pan peeking out the flash hole. The heat of the flash, not the direct fire it what sets it off. With a set up like that it is almost cheating. I would bet it would fire often with out prime. The point is the flintlocks can be very reliable.

One you have experienced the difference between an exceptional lock and the rest you are spoiled. If you are fooling around to make it reliable there are issues that need addressing. It could involve tuning or more. I started with a first gen TC flintlock. It was a miserable piece of junk. All the others have been somewhere in between the TC and the Kiblers.

I had a Pedersoli Hatfield. The flash hole was too small. The extra long breech plug was a problem. I got an RPL lock for it. I also opened up the plug chamber and flash hole. It then worked like a champ. After, I fussed with the original lock and made it work just as well as the RPL.

Sounds like the OP's lock lights the prime OK. The first thing I would do is open up the flash hole to 1/16". Then possibly open up the powder chamber in the plug. IF the lock does not spark well, find out why and fix it. Shortening flints?? Perhaps the sear nose is too short and the the half cock is to far foreword? I think that was one issue I addressed, I made a new sear.

Good luck.

Click to expand...

I've read a good lock will fire 50 percent of the time with no prime in the pan and will also fire reliably up side down with a normal prime. Now exactly where you could use the later example would be a question of curiosity but does speak to reliability.

You mentioned adjusting the flint so it does not rest on the frizzen at half cock. I think this is an important change. As mentioned above, a flash hole 1:16” in diameter tends to work well.

Can you video the lock using slow motion on your phone? This may give you a better idea of what is happening.

Below are a couple freeze frames from my rifle. It has a Chambers large Siler lock. I use Goex 2F or Schutzen 3F for both the primer and main charge. The photos below are using Goex. My main problems have been dull flints or residue on the frizzen and flint.

Every liner I've ever acquired had only a tiny pilot hole much like rear sights with their tiny "starter" notch. I drill them all out to 1/16" which as always worked perfectly. I've fired them without prime and upside down and ignition was about 1 in 5 shots with no prime and 100% ignition upside down.