Shortening lock time

[Tom Compton]

Black Jaque, can you tell if the perceived delay is between sear break and pan flash or between pan flash and ignition? If the latter a too small flash hole could be the problem.

 

[Larry Pletcher]

Pletch,

You wrote that the differences in your flint tests were not enough to be noticeable to the human senses. So that would mean that the 0.0091 second difference between the fastest time and the slowest time were not perceptable to those witnessing the test.

Do you have any information on how slow a lock has to be in order for the human senses to pick it out?

My Chambers lock has a just o-so-slight delay that I can perceive so I am curious how bad that really is.

I am sure this would be different from person to person, but there must be a threshold that human's can't perceive (just as they know a motion picture has to have so many frames per second for humans to view it as fluid motion.)

You realize that what I saw in tests my not be a good answer because of a number of reasons. First, My fixture used a car lock solenoid to smack the sear when I pressed the space bar on my computer. I'm pretty well insulated from an intimate contact with the lock.

As for a delay explanation, place yourself in the middle of a series of 20 trials. In this case I'd try to guess whether the trial I just heard was faster or slower than the previous one. I was wrong half the time.

Using numbers as an example, lets drop to 3 decimal places. The lock is averaging around .040 seconds. I might be looking at times from .037 to .045. I can't tell the difference. I get a time of .055 - still can't hear the difference. But, looking at the time, I begin to think the flint needs knapping. Next comes a .046, and I decide not to knapp. Next trial is .079 - and I could hear that one. I knapp the flint and the next three times are .055, .046, and .037. (The first trial after knapping has never been the fastest time.)

I sometimes felt a time had to nearly double for me to hear the difference. This could be fatigue; I don't know. I do know that I can't hear a .030 difference. A .050 difference I can probably hear.

On a gun, if you can hear a difference, my gut says it is more likely to be a slow vent. (I think hang fires vent related.) In my tests there are no vents, just a photo cell reading the pan ignition. (If you fired your lock with no barrel charge, that would be closer to the feel I get in tests.)

I'm guessing this is way more than you wanted. And, I'm not sure my experience transfers well to the lock on the gun.

Regards,
Pletch

 

[Black Jaque Janaviac]

Oh. Ok. Your times are just the time to ignite the pan, not the time to ignite the main charge.

My vent is drilled with a #50 bit.

When I dry-fire with just a pan charge and nothing in the barrel the lock seems to work instantaneously. But the main charge seems to have just a slight hesitation.

 

[Larry Pletcher]

Oh. Ok. Your times are just the time to ignite the pan, not the time to ignite the main charge.

My vent is drilled with a #50 bit.

When I dry-fire with just a pan charge and nothing in the barrel the lock seems to work instantaneously. But the main charge seems to have just a slight hesitation.

You're are probably right in the ball park. When I'm timing locks only (no vent) a space bar press and the pan ignition seem instantaneous too, even though I know there is a .040-.050 delay. I simply cant hear it.

I have timed vents by using a photo cell at the pan to start time and one at the muzzle to stop time. Doing that I get vent times in the .036 (best) to .050 range. If you added a good lock time (like .042) to a good vent time (like .038) you'd get .080 seconds. That would be a similar delay to the time I mentioned in that earlier post, and that I think the human ear can detect.

One could throw in the time a set trigger takes to really get picky. I would like to time a set trigger but haven't figured out how to set the experiment up yet.

The link below is to a series of experiments dealing with vents:
Pan/Vent Experiments

Regards,
Pletch

 

[Artificer]

Pletch,

With your research that showed faster or the fastest ignition times with the powder banked toward the vent, I wonder if this is why we see original paintings and drawings where people turn a Wheel lock or Flint Pistol on its side so the lock plate faces upward?

Gus

 

[Larry Pletcher]

Pletch,
With your research that showed faster or the fastest ignition times with the powder banked toward the vent, I wonder if this is why we see original paintings and drawings where people turn a Wheel lock or Flint Pistol on its side so the lock plate faces upward?
Gus

Hi Gus,
You could be right. I don't know. I'm not very good with that type of paintings; but appreciate you bringing up the possibility. It would be cool if the things we learn were already known in wheel lock days. Maybe we just need to try harder.

Thanks, Gus. I appreciate your post.
Regards,
Pletch

 

[Artificer]

Pletch,

There is an original drawing/engraving of Two Cavalrymen armed with Wheel lock pistols and coming at each other. I know I have seen it in at least two or three books, but I can't seem to find it on the web to link to it. It may even have been listed as a duel, I just can't remember.

What is notable is they have the pistols held on their sides with the lock plates up. When reading your information on priming powder up against the barrel/vent, that is the first thing that came to mind.

Thank you for your answer and even more so for the testing you have done on ignition times, that you have so graciously shared with all.

Gus

 

[Dphar]

Instant is not possible. People who claim, for example, that their FL is as fast as a percussion are dealing with a really screwed up percussion.

Stiff springs in a well made and engineered lock and an internally coned vent liner that puts the powder close to the priming.

Dan

 

[Dphar]

Consider the firing cycle of the FL. Cock has to travel to the frizzen, it has to scrape the flint down the frizzen pulling off hot bits of metal and uncover the pan. The sparks have to heat the priming powder granules to ignition temp. The flame has to propagate through the prime and build heat. The priming flash has to heat the main charge to ignition temp. Then the flame has to propagate through the main charge to build pressure to expel the projectile. Lock time is relative. The variations in time of a FL from shot to shot are greater than the total lock time of a Remington 700. A fast flintlock is far slower than a percussion which blasts a jet of high energy hot gas into the min charge when the hammer strikes the cap. The compound in a cap is a detonating compound and is pretty hot stuff. If used as a main charge no firearm could contain it. Flintlocks work off radiant heat once the priming is lit off.
It all takes time.
Dan

 

[Black Jaque Janaviac]

Dan,

Perhaps I'm just expecting too much from my flintlock, however when I've asked others many people say they cannot tell the difference between firing their flintlocks vs. caplocks.

When I first began with a flintlock I had a Pedersoli Kentucky .32. I too could not perceive a difference between that and my caplocks. I'm not claiming that the Pedersoli was just as fast, just saying my senses could not detect the difference.

 

[Larry Pletcher]

Hi Dan,
I think I can collaborate your comments by taking numbers from three different experiments. The fixtures and dates are not the same, but I feel confident in making at least a ball park conclusion.

In many tests I timed locks from sear press to pan ignition and got numbers from .0300 to .0450 seconds with very few better and many worse. In another experiment I timed vents and under best conditions got .0360 to .0380 seconds.
Adding a good lock time and a good vent time, I feel confident in saying that we can expect a flintlock to barrel ignition in the area of .070 to .080 seconds.

In a third experiment I used equipment holding a Chambers pistol stock, Siler small percussion lock and a barrel stub. The Small Siler clocked in at around .020 seconds, as did a mule ear percussion. But --- the barrel ignited with the cap detonation. So from sear press of the percussion to barrel ignition was in the .020 range. ( I also have watched a slow motion of Lowell Gard's small Siler cap lock that confirmed this.)

Taking these three experiments together, I feel that we can conclude that a flintlock is at a time disadvantage of .050 seconds -- give or take. Please remember that these were done on different days, different fixtures, and different conditions, so I am aware that this is only a ball park conclusion. I am confident of each individual test, just not sure one can put it all together.

Regards,
Pletch

 

[Tom Compton]

Thanks, Pletch, for all your work in this area. Iv viewed a lot of your experiments but the summation helps greatly.

I must say I'm still taken aback by the time consumed between sparks reaching the pan and primer ignition.

Merry Christmas!
TC

 

[Black Jaque Janaviac]

I must say I'm still taken aback by the time consumed between sparks reaching the pan and primer ignition.

Actually I'm more impressed that it can be as fast as it is. Heck I'm flabbergasted that the thing goes boom. Not that I get frequent missfires. . . it's just that when I think about all that has to happen flintlocks seem like a Rube Goldberg "better mousetrap".

...And that is precisely why I love shooting them.