Dieseling

[Many Klatch]

I didn't want to drop this subject into the Remnant Embers thread in the Flintlock Rifle section. If you haven't seen it you should go look. There are a lot of good safety ideas.

Anyway. This happened to a friend of mine at Friendship a couple of years ago. I was shooting at another station a little bit down the valley so I wasn't right there but I saw him and the witnesses about 2 minutes after.

He had been shooting his smoothbore and was getting ready to load again. He had just poured powder down the muzzle when the range was closed so they could change the targets on the Seneca Run match. He dumped out the powder, ran a wet patch down the bore and then stood around talking with his buddies for about 15 minutes until the range was reopened.

He then ran a dry patch down the bore and all of a sudden "FOOOM" the ramrod shot about 30 feet in the air.

We have discussed this at length around numerous campfires and have come to the conclusion that spontaneous FOOOM was caused by dieseling. The shooters who happened to be in the immediate vicinity probably have a combined total of 175 years of experience shooting flintlocks. None of them had ever seen anything like it.

We think that the gun was hot from shooting. The wet patch packed the left over powder over the touchhole. It dried out due to the warmth of the barrel. When he put the dry patch down the barrel the air compressed due to the plug over the touchhole and must have ignited the powder by heat. I know that isn't supposed to happen but we can't come up with any other explanation. I can't believe that there would have been a smoldering ember down the barrel with powder packed around it for 15 minutes without an ignition. You would have thought that the wet patch would have taken care of any embers.

Nobody got hurt. He did not have his hand over the end of the ramrod and the barrel was pointed up and not at anybody. The ramrod was recovered unbroken and examined and nothing was seen that could have lead to the FOOOM.

Anyway the moral of the story is Muzzle Up, Don't point the Muzzle in any direction other than the target and don't put your hand over the ramrod or muzzle.

 

[Grizzly Adams]

When I load my flinter after a few shots, I have to be very careful about the air pressure being generated. A couple weeks ago, I was seating a ball and I bounced the ramrod on the charge when it shot 10 feet into the air, the compressed air pushed the ball about 2/3 back up the barrel. I was able to catch the rammer but I got a bunch of very strange looks. Thankfully the charge did not go off and I had the muzzle pointed away from my face. Regardless of the charge going off of not, a rammer coming out at the speed it did would not feel good going up my nose. :shocked2:

 

[Billnpatti]

Wow! I'll have to admit that you have a heck of a puzzle on your hands. If this was a friend of a friend story, I would put it into the category of rumor or a dreamed up story but since you witnessed it first hand, I accept that it did happen just as you say. However, I am as puzzled as you all are :hmm: and I have no reasonable explanation. For dieseling to occur, he would have had to really run his patched rod down the bore mighty fast and hard in order to compress the air enough to ignite anything. I have tried to use one of those doo hickeys that is supposed to ignite tinder when it is compressed inside the cylindar. I tried and tried and never could get enough compression to heat the air inside the chamber enough to ignite the tinder. So, I know how hard it is to ignite anything by compressing air by hand. But, other than the remote possibility of deiseling having occurred, I have no idea what could explain for what all of y'all saw. :idunno: I'll be interested in reading anybody else's ideas.

 

[cositrike]

Whilst loading a small calibre smoothbore, the ramrod sprung back (air pressure). The percussion cap AND nipple were removed in order to hopefully blow out whatever was causing the blockage. I then pushed the ramrod back down the bore and although tight started to move. I pushed down hard on the rod, in order to complete the load and BANG!! 40cal ball, ramrod and parts of a silver finger ring went through two of my fingers. Compression ignition, or dieseling can be the only answer, as there was no ignition source
Simon

 

[jamesthomas]

Its called using to tight of a patch, ball combo. The combo some people are using is so tight that the air is being compressed it doesn't have time to escape through the vent liner, touch hole, nipple or around the patch its self.

 

[necchi]

:hmm:

 

[hanshi]

Not "dieseling" at all, just a charge set off by a SPARK! A gun is not an internal combustion engine burning diesel fuel.

 

[Grizzly Adams]

The term dieseling here is only being used to describe the method of igniting the powder. Just as a Diesel engine uses the compression of the piston to superheat and ignite the fuel, the compression of the roundball being pushed down the barrel is acting like a piston, heating the air and possibly igniting the powder :wink:

 

[George]

I agree with Hanshi, something other than dieseling/compression ignition is going on. Don't quite understand how anyone could believe that could happen. Not reality based, IMHO,

Spence

 

[Tinker2]

Sounds like touch hole/nipple was plugged, tight patch built up compressed air
Never seen that shoot a ramrod more than a few feet, most don’t clear the barrel
Impressive to see I’d bet



First time I saw a gun “diesel” was 1969 just a barrel with a jacketed bullet
stuck half way down the bore

Put penetrating oil in the barrel and a brass rod just under bore size and with a
hammer planned to pound it out.

Well the oil around the rod helped seal it and hammering created heat.
When it went off it had more than enough power to have been deadly



William Alexander

 

[Alden]

Kids "Diesel" pellet gun shots with a drop of oil. I don't know what kind of pressure is necessary but one of the engineers here can figure out how many atmosphere's we're talking about and determine if that's enough to ignite gunpowder and/or the lube.

Some say it doesn't happen and I was a doubting Thomas, but there are three examples given right here in this thread. I'm a believer!

 

[George]

Some say it doesn't happen and I was a doubting Thomas, but there are three examples given right here in this thread. I'm a believer!

We don't discuss religion in these forums, and that's what it would take to make this one true, belief without evidence.

Spence

 

[Stumpkiller]

Atomized diesel fuel takes about a 20:1 compression ratio to set off with a catalyst present. For solid powder you'd have to get the pressure to raise faster than the vert/cap channel could allow it to escape, and I'm not sure with your fingers alone you could generate the push needed in one fast ram.

 

[tenngun]

I was not thre and can not come up with any idea as to what caused it. How ever one would think you would be looking at 15-17 to 1 compression to get this to work. A .62 is about a 1/3 sq inch. Each unit of compression would add about 5 pounds of resistance to the ramrod force. We are looking in the nabirhood of 70 pounds of pressure on that rod, and at least 15 atmosphers of pressure on the vent with out clearing it. One would think as the shooter readjusted his hand postion the rod would slip up.
If we could go back and see this we may see that the shooter thought he swabed, just as we all have dry balled..but I wasn't there. For it to have happened with out a spark it had to be one of those 1 in a million all chips landing in the right spot sort of things.

 

[Zonie]

I have no doubts about dieseling being a possible cause of a black powder charge to ignite.

It would require a tight fitting piston like a patched ball or a tight fitting cleaning jag with a patch on it.

It would need the vent hole or nipple to be plugged.

It would need a small amount of black powder in the barrel.
A long barrel would increase the possibility and the patched ball or cleaning jag would have to be rammed to the bottom of the bore in one smooth very rapid stroke.

For some numbers and I know how many of you love numbers lets take a barrel that is 30 inches long and assume the "piston" can be rammed to within 2 inches of the bottom of the bore. That would create a compression ratio of 30/2= 15 to 1.

Many diesels run on compression in this neighborhood. (Diesels have compression ratios of 15:1 to 25:1).

The temperature of the compressed air will be around 990 degrees F. The air pressure will be about 217 psi.

With a .54 caliber bore the strength needed in addition to overcoming the friction of the piston to develop 217 psi will be 49.8 pounds.

Black powder has an ignition temperature of less than 990 degrees F so if you know someone that can cram the patched jag or ball down the sealed bore with a 50 pound force you may get to see some exciting action.

I should add here that if the bore had a leak at the bottom like an open vent hole or nipple, much of the compressed air will leak out.

If the jag or patched ball was shoved down the barrel like it should be in short strokes, much of the increased air temperature will be absorbed by the walls of the barrel.
Also, by ramming the object down the bore more slowly, in steps (like we all should) will allow the built up air pressure to leak out.
It also lessens the likelihood that you will break your ramrod.

Summing this up, yes, I'm sure it is possible to have a BP gun fire from compression alone.
No, if common rules of loading are taken the likelihood of the powder igniting is very very small.

 

[jethro224]

The guy this happened to is a friend of mine also and I have heard his story straight from the horses mouth. The way I heard it he dumped the powder out and ran a moist patch down his bore and just let it sit with the brass ramrod in the barrel while they waited for the range to re-open. I don't recall if he switched to a dry patch or not but he then scrubbed briskly up and down a few times before the leftover powder ignited.

His gun is a 28 bore flintlock with a 42 inch barrel. It was already dirty from shooting. His rod was solid brass with a jag. He is no weakling. He normally shoots 60 grains of 3F, I assume that was his original load before dumping it out of the muzzle. I know that all of the loaded powder will not dump out just by turning the muzzle down but I don't know how much would stick to the fouled barrel walls and the breech face. I do believe his story. There were multiple witnesses.

 

[necchi]

So, What was his lesson?
I mean something like that doesn't happen without learning something.

 

[M. De Land]

Makes me wonder how safe our range rods are with the big balls or T handles on the ends that are routinely used by the palms of our hands.

 

[pargent]

This is why range rods with T handles are band from our SSAA ranges

 

[Alden]

Some say it doesn't happen and I was a doubting Thomas, but there are three examples given right here in this thread. I'm a believer!

We don't discuss religion in these forums, and that's what it would take to make this one true, belief without evidence.

Spence

Spence, the evidence is pretty clear to me...

It has happened to the exclusion of any other ignition source and now we know the specific scientific parameters behind how/when.

Now, if they just hadn't staged man landing on the moon...