Detonation ?

[atr]

Although i wasn't there , this story comes directly from some who were . On one of our local ranges there were a lot of handgunners out when a guy showed up with a single shot , large caliber , flintlock pistol . Folks were watching him as a flintlock pistol is unusual around here . He got a couple of rounds away and then got a ball stuck in the barrel about 2/3s the way down . He held the barrel with his left hand and with his right he reached into his shooting bag and withdrew a brass hammer . He smacked the steel ramrod smartly and the gun fired . He released his grip or it recoiled out of his hand and the gun hit the ground . The brass hammer was found about 10 yards out front and the ramrod was found at double that distance . The sequence of events precludes priming the pan before loading the gun and the gun was not cocked or on half cock . What caused it to fire ? I don't know the brand of powder or the granulation size but there is speculation that it fired when the powder was sharply compressed . With no prime in the pan and the gun uncocked what else could have caused the detonation ? I think we can agree that hammering a ramrod home is not a sound practise but is the practise unsound because black powder will detonate with a sharp impact in a confined space ? I've always rammed making sure that no part of my body except my hand is over the muzzle and now i question the 'T' handled rods where you see guys placing thier shoulder over the muzzle . I've wondered if the cock disengaged with the hammer blow and although there was no prime in the pan a spark found it's way through the touch hole . Maybe not . Maybe it detonated under a violent compression .

 

Black powder is impact sensitive. One would have to work at it to get the stuff to blow under impact, but it can and has happened.
As you surmised it could also have happened if the cock released and the flint hit the fizzen and a spark got into the touch hole. That's why a flinter should NEVER be "dry fired" without a priming charge but the barrel loaded as that shower of sparks can easily as not find it's way into the vent hole.
I've shuddered watching idjits at the range literally THROW a metal range rod down on top of the seated ball/bullet so hard the rod bounces! Why they do this I have no idea, but the risk of deonating the charge is present. Thowing the rod down on the charge is STUPID. :shake:
Hammering the metal rod weren't none to bright either. :shocking:

 

All I can coment on this, is that in tests, so far, the testers, Police Government Forensics Departments, have been unable to detonate BP by prcussion shen in the can. Out of the can and in the barrel as noted, the possibility is certainly there. Perhaps this is the first known instance!

 

[musketman]

The person is lucky he still has his hands attached to his body, let alone running the risk of killing someone by a flying brass hammer and ramrod......

Though he used a brass hammer, the rod was steel and could have produced a spark (steel rod against a steel barrel) that sneaked pass the patch and detonated the powder...

 

In a recent MuzzleBlasts mag article the Bevel Bros. ran tests similar to the situation you describe to see if they could set off the powder---they had to work at it. Also, there is a fire starter which works on a similar principle--that is very fast compressional heating.

 

[robinghewitt]

A cloth wrapping for the flint perhaps? Hawker warns us that such a thing can hold the spark. When he rammed the load powder might have sprayed out the touch and found fire.

Well, it's as likely as anything else ::

 

[connerm]

The good thing is that it was pointed downrange. Maybe the barrel was still hot from the previous shots. Good-thinking Mike Roberts is dead on with his hunch about the fire piston. This is no joke and I have seen dozens of fires started with one. http://www.firepistons.com/ After learning the bow and hand drills, I was blown away at how easily these guys, girls and kids, got a glowing ember. The factors involving the stuck ball in the flintlock pistol sounds like the same factors necessary for the fire piston. Excellent thread. Thanks for submitting it.

(Although its perfectly ok with me for others, I would never have a flint or percussion set up that required me to use a hammer)

 

Mike brings up a very valid point - that of compression heating. As well, the air, forced through the powder and out through the touch-hole at high velocity will also produce heat at that venturi point - right in the powder. This heat is instant and very high in temperature. I presume several factors came together,(along with the planets) to promote ignition. I don't believe any sparks or lingering sparks were the cause - not for an instant. Now, that said, there is a possibility of hot or warm fouling to combine with the heat of compression. There is too long a period of time between loading the powder, and trying to seat the ball and getting the it stuck, whacking away at it - etc, for a spark to still be there and not have touched off the charge as it was dumped into the breech or anytime afterwards. Nope- no lingering sparks. That doens't compute as being possible.
; Also, detonation isn't the fact here either. Had the charge detonated, the gun would have as well. The charge merely went off prematurely. Not a big thing- but detonaton is much too strong a word to be repeated when talking about this accident in the future. Detonation is a word that governments wil use in attemps to regulate powder further- as they are trying to do in Canada right now. They are trying to use the word detonaton where there is none- just burning as in a fire- detonaton impesses those with no knowledge & gathers their votes. No - no detonation here - the pistol fired, and that's a fact.

 

Daryl: I see your point clearly. There was NO detonition. That is another term entirely. The arm fired when it should not have.
Detonition is an explosion, pure and simple and would have blown the gun apart.
We studied the phenomena of detonation when we were in police competition and revolvers loaded with just 2.7 grains of Bullseye were blowing up. Literally. I mean pieces parts, fragments, junk! We all thought there was a bad batch of Bullseye floating around, but Hercules sent different lots of Bullseye to H.P.White Labes for testing.
Interestingly there was nothing wrong with the powder, the stuff was detonating (let's just use the word EXPLODE) due to the way it lay in the case. (one reason)
If the powder were close to the primer, more or less in one place, it would behave properly, but if it lay along the legnth of the case, the primer would set it all of at once casuing an explosion (detonation). There were other reasons, i.e. the primer blew the small amount of powder into the air filled case where every grain burned at once casuing an explosion. This is the primary reason loading density is so important. The more full the cartridge case the better.
Another of my passions is high powered spring air guns. Air compressed by the air gun spring can cause the air to become super heated for a fraction of a second to the tune of 2000 degrees! That's why you NEVER use oil in an air gun. Why? Super compressed oil air mix at 2000 degrees causes what? AN explosion or detonation. This has happened several times. An air gun can and will blow up very nicely thank you! :nono:

 

[Deadeye]

Re compression heating, Muzzle Blast June issue has an article on that and their conclusion was that it was , in their words, "virtually impossible" to set off black powder in a rifle or smoothbore by compression heating. Not saying they're right just passing it on.

 

[atr]

Hey Maxiball , me to . R1 , R7 , R9 , RX2 , HW-45 , RWS 35 , RWS 350 Plus Crosmans and lots of el cheapo stuff . I just bought a Hatsan 55 in .177 that i believe is sold in the U.S.A. by Winchester . The first 50 shots went supersonic as the oil denonated under compression . After 500 rounds it's settled in at 880 fps with cpl's . For a cheap gun is it ever accurate . Cattails at 60 yards .

 

[Stumpkiller]

Hey! I used to get my RWS 45 to shoot about 1,500 fps by putting a drop of oil in the intake hole. Sounded like a .22LR Stinger when it went off. Destroyed the seals in about 30 such firings

Now I have a Beeman S1 and I don't play that no more.

Still, it would take a h*ll of a hammer whack to get the compression a 30# spring with an 18" lever produces. I don't think you could do it with one of the little brass hammers normally carried for flint knapping.

Still, pounding on a loaded gun with a hammer. . .

 

[Zonie]

Cattails at 60 yards? Were you aiming at the cat and only hit the cattail?::

The study done by the Bevel Brothers in Muzzleblasts was done in a short pistol barrel. They found that it usually fired on the third whack with the hammer on a metal ramrod.
From this, they concluded that there was little possibility of black powder being fired just by compression.
I don't recall the exact length of the barrel but if it was 10 inches long and they compressed the air column down to 1 inch of powder they would have had a compression ratio of 9:1.

I wished that they had done the same experiment with a long barrel like 30 inches and compressed the air column down to 1 inch. At a 30:1 compression ratio, I am sure their results would have been different. IMO at that ratio, it would have fired on the first RAPID downstroke.
Just one reason, I don't ram the ball down fast.

For those who read MuzzleBlasts, in the letters to the editor, a writer did some fancy calculations which IMO were not done at all correctly. From this, he concluded that there is no temperature rise caused by compressing a column of air!
Anyone who knows how a diesel works knows that that conclusion pure hooie!

 

Maxiball- we had a bunch go at Regina and found the Dominion ammo we used in the Force, suppose to have been loaded with 158gr. RN or SWC lead and 3gr. Bullseye, had in fact been loaded with 7gr. or 8gr. or whatever fit into the case. It was a deliberate sabotage by workers in the Dominion plant who were having difficulty with magagement - I was told.
: Several guns literaly disintegrated when starting on the 'new' case of ammo. Of course they halted shooting immediately, and expamined the rest of the ammo. Rougly 1/2 the boxes of ammo had overlaods in them.
: This all happend back in the late 70's early 80's when the mounted Police were still packing .38's and shootng 158gr. RN or SWC.

 

That's probably correct, however the Daisy caseless .22 ammo, was ignited by comressed air.
: For some reason, at some place in time, all the correct circumstances are in line and bingo! something, virtually unexlainable happens. Luckily no one was hurt, this time.

 

Aha! more airgunners out there than I knew about!
I was very surprised with a cheap Gamo Wal-Mart Shadow .177 for $124 bucks, cheapo scope 4X gave 0.4 at 25 yards with Kodiak Match pellets. IF you could hold really , really stady with that horrible trigger. I quit using a come-along to fire the thing when I realized a jack handle in the trigger gaurd worked better!
Worse trigger ever on naything!
opppps. Wrong forum huh? Wonder could we start a black powder airgun forum? naw, guess not.
Cats at 60 yards would be MCUH better than cattails! :RO:

 

[robinghewitt]

they concluded that there was little possibility of black powder being fired just by compression.

I think they are right. But wasn't there a patent ignition system back in the 18th, that used a fire piston to light the powder? Or did I dream it? ::

 

[musketman]

they concluded that there was little possibility of black powder being fired just by compression.

I think they are right. But wasn't there a patent ignition system back in the 18th, that used a fire piston to light the powder? Or did I dream it? ::

Robin: you are not dreaming, I can see where this would set the powder off, especially if the vent got plugged by fouling and the air couldn't escape...

Fire Piston

 

Fire Piston - most interestng- thankyou for that information & knowledge.

 

[more powder]

Hi to all New guy here. Do think this guy with hammer was using some kind of lube that caused the gun to go off there are gases that go off under compression,the fumes from the patch colecting in warm barrel ,or the fumes jetison out the touch hole just a thought.