Flint Orientation

[Dphar]

See my article:
[url] www.chuckhawks.com/flintlocks.htm[/url] concerning the tuning and shooting of flintlocks.

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I would have to politely disagree with at least part of your article.
The statement that a flintlock, all things being equal, will light the charge before a percussion lock of equal design can strike the nipple is simply not supportable by facts.
1. Even if the flint cock is of the same weight as the percussion hammer, which is very unlikely if both are sporting locks, the flint hammer will not put sparks in the pan before the percussion hammer strikes the nipple. The flint striking the frizzen and imparting energy to it slows the cock, scraping away bits of metal from the frizzen requires energy as well.
2. The persussion hammer striking the nipple lights the main charge directly. Even if it did fall slower the main charge will light faster in the percussion unless it has very poorly designed flash channels.
The flintlock must make sparks, the sparks must be thrown into the pan and the sparks must then impart enough heat to the priming to start it burning. The priming must then propagate enough flame to transmit enough heat to the main charge to start it burning. It is very hard for the actual flame of the burning priming to enter the touch hole since it would have to pressurize the air/powder charge in the barrel to do this so the fire is conducted almost totally by radiant heat. This takes time. In fact most of the lock time in a flintlock stems from this sequence.
The percussion cap fires when the hammer impacts it. While I do not know the "burn rate" of the compound in percussion caps it is likely several thousand feet per second perhaps in excess of 10000 since it is a DETONATING compound. It does not burn as BP does since detonating compounds are not surface burning as BP is. Since for our purposes the priming compound instantly converts to hot expanding gases and these are spread to the main charge at the bottom of the nipple even in poor designs like a drum and nipple ignition of the main charge is far faster than the time it takes the priming in a flintlock to generate the heat needed to ignite the main charge.
But just like flintlocks there are bottle necks in percussion systems. I have had one percussion rifle that was about as fast as a good flintlock but it had a screwed up breech.
A good breech design places the powder at the base of the nipple. The pressure generated by the detonating cap is nearly all transmitted through the nipple to the powder if the percussion lock is properly made and the hammer correctly contacts the nipple. Thus a high pressure jet of hot gas is transmitted to the powder rather than at best very low pressure flame and likely only radiant heat is applied to the main charge though the vent of a flint gun.
The percussion version of the L&R "Manton" is VERY fast. I built a pistol some years ago using the guts and hammer from one of these and TOWs Hawken Pistol breech. It was VERY fast. Fully equal to most exposed hammer cartridge firearms from shooting impressions.
While it is not possible to provide actual lock times without high speed photography it is simply not possible for a a flintlock mechanism to light the main charge as fast as a percussion with a reasonably well designed breech. The flintlock has too many operations to perform. The percussion hammer, powered by a similar spring simply has to strike the nipple with nothing to slow its travel except the fly if the lock is so equipped.

Dan

 

[paulvallandigham]

Fair minded men can disagree, Dan. I have seen my rifle, and others, put the sparks into the pan and ignite the priming powder before the cock finishes its stroke. When I do it right, my main charge is actually igniting before the cock finishes its stroke. The first time it happened to me, It thought it was a fluke, and the guy next to me asked me if I had a " cook off "? I must have done something different on the next loading because the timing was fast, but not as fast as that first time. But, then, the next shot went off as fast as the first did, and my friend decided to sit and watch what I was doing. Sure enough, he said it looked like one of the close plays at first base in a major league game, where the ball gets to the first baseman's glove a split second before the player's foot touches the bag. He was and remains a long time cap and ball shooter, and he was almost in shock. He called all the other C&B shooters over and had them watch with him the next time I fired a shot. I did it again. Sometimes, now, I get a tie, where the main charge ignites just as the cock finishes its fall. But most of the time, its going off before the cock finishes. I am slowly getting use to the speed, but I still find myself smiling when I know my gun is going off faster than, I, and a lot of experienced shooters ever thought was possible.

One tip: The angle of the flint to the frizzen has to be that 60 degrees at impact, in order for the sparks to be thrown into the pan. If the sparks merely roll down the frizzen and fall into the pan, my gun's ignition speed will beat yours every time. That requires tuning that frizzen spring correctly so that it pops over and open as soon as it is struck. Only then does it get out of the way of the sparks being thrown into the pan.

 

[Dphar]

Fair minded men can disagree, Dan. I have seen my rifle, and others, put the sparks into the pan and ignite the priming powder before the cock finishes its stroke. When I do it right, my main charge is actually igniting before the cock finishes its stroke. The first time it happened to me, It thought it was a fluke, and the guy next to me asked me if I had a " cook off "? I must have done something different on the next loading because the timing was fast, but not as fast as that first time. But, then, the next shot went off as fast as the first did, and my friend decided to sit and watch what I was doing. Sure enough, he said it looked like one of the close plays at first base in a major league game, where the ball gets to the first baseman's glove a split second before the player's foot touches the bag. He was and remains a long time cap and ball shooter, and he was almost in shock. He called all the other C&B shooters over and had them watch with him the next time I fired a shot. I did it again. Sometimes, now, I get a tie, where the main charge ignites just as the cock finishes its fall. But most of the time, its going off before the cock finishes. I am slowly getting use to the speed, but I still find myself smiling when I know my gun is going off faster than, I, and a lot of experienced shooters ever thought was possible.

One tip: The angle of the flint to the frizzen has to be that 60 degrees at impact, in order for the sparks to be thrown into the pan. If the sparks merely roll down the frizzen and fall into the pan, my gun's ignition speed will beat yours every time. That requires tuning that frizzen spring correctly so that it pops over and open as soon as it is struck. Only then does it get out of the way of the sparks being thrown into the pan.

I think you should study some of the high speed videos of flintlocks in action. If you do you will notice that none of them, original or contemporary ignite the priming before the cock is stopped. This includes Mantons and other high quality English locks that were built purely for speed with decades of development for that purpose. You will note that the sparks bounce around in the pan before the powder actually ignites. This is well after the cock stops moving.
When the percussion system was invented the English dropped the flint system for shotguns like a hot rock because of the difference in lock time. It took a little longer for them to whole heartedly adopt it in rifles (according to George in British Guns and Rifles) but the percussion made wing shooting so much easier that it quickly replaced the flintlock.
In fact the advancements in flintlock lock design by the British were done to make wing shooting easier by reducing the delay from the time the trigger was pulled until the shot charge cleared the muzzle. The lightened parts, low friction links for the mainspring etc etc. Nocks breech was intended to produce quicker ignition and better velocity for this reason.

Dan
[url] http://www.youtube.com/watch?v=h7PsqljH8Fk[/url]

 

[rickystl]

I don't believe it!! I just finished posting this question in another section of the Forum. Thanks for the Link Roundball. :thumbsup:

 

hey squirreltail i,ve a traditions penn. longrifle that used to destroy flints,i switched to lead around the flint, don,t know why but it works,use lead wrap in my 2 other rocklocks too,