Vincent van Gogh, 1890, death by a bullet


#1

Here is a new theory of van Gogh’s death foxnews.com/world/2014/11/19 … latestnews. In this discussion “powder tattooing” is mentioned, which, I assume, is a halo of un-burnt gun powder under the skin around the bullet entry. I am aware that not all the gun powder is burnt and some comes out of the muzzle. Why not to develop a 100% burning powder so there is less fouling and better pressure? Surely modern chemistry and computer science would allow for that.


#2

There are powders that can do that under the right conditions. But, it would be impossible to develop separate powders for every conceivable condition of bullet weight and diameter, pressure, velocity, barrel length, etc. And, you would still have the hot gasses that will follow the bullet and probably do more damage than the un-burnt powder.

It would probably be more feasible to develop a gizmo that can be attached to the muzzle to capture the gasses and un-burnt powder.

This sounds like the beginning of another “Forensic” TV series. ;-)

Ray


#3

You both seem to have smokeless propellants in mind. When van Gogh shot himself, it was with black powder. On burning, a large part of this turns into solid substances instead of hot gas. No way to change this.


#4

Yes, in 1890, even though smokeless powder had been invented, very little of it was being used by civilians. Most every common cartridge at that time was loaded with black powder. It wasn’t until about 1900 that smokeless powder came into wider use, but black powder loadings were still manufactured, and would continue to be for several more years.

If you are ever around a heavily used small arms firing range with a concrete floor, you will be surprised by the amount of unburned smokeless powder which accumulates in front of the firing line in a fairly short time.


#5

I don’t think Vlad’s question was about the type of powder that was in use in 1890. The van Gogh reference was simply a lead-in to the question of why modern chemistry cannot develop a powder that is consumed in the barrel of a firearm rather than expelling unburned grains.

Ray


#6

powder tattoo
Forensic pathology A geographic appearance on the skin caused by a gun fired at close range, in which the still-burning gunpowder embeds in the skin and cannot be wiped away; the PT helps determine whether clothing was worn over an entrance wound.

I guess Ray understands me better that I do myself. I was asking about modern powders, since there were major scientific developments since Vincent shot himself (although no gun was ever found).


#7

I believe that nothing in a burning or explosive process is ever 100% consumed, and that includes nuclear material in a nuclear explosion. The very process of burning in a chamber is going to accelerate powder grains down the barrel as the gasses are accelerated down the barrel to push the bullet. Powder grains, or partial grains will be accelerated down the barrel as they burn and upon leaving the barrel some will be cooled rapidly enough to leave a residue.

Residue from partial combustion and even complete combustion is also ejected form the barrel and perhaps that is one of the things that leaves the powder marks or powder burns on a close target.

Complete is almost impossible to achieve. Thermodynamics demonstrates that a conventional combustion and explosions are essentially the same process and both are composed of combustion waves or detention waves, usually a large number of one or both interacting. As the combustion front or wave pass through the mixture of fuel and oxygen it typically accelerates and when the velocity of the burnt material behind the combustion zone reaches mach 1 relative to the combustion zone, the combustion wave collapses into a form of shock wave with tightly compressed oxidation on at the back of the shock front. This is termed a detention wave. Both of these activities cause great turbulence which makes complete combustion or detention essentially impossible.

From a practical standpoint achieving a higher burn rate of the grains in the barrel will reduce the unburned residue, but this will also cause a pressure spike in the barrel. A longer barrel will increase the burn time and increase the reduce the unburned residue as well. All this is also a function of the type of powder and the shape of the powder grains.

Much effort has been focused on achieving high rates of combustion with great success in some areas, like reducing carbon monoxide emissions but 100% combustion is an elusive target in the best of circumstances, and the barrel of a gun is a tough place to achieve it.

There are cartridges which do not allow unburned propellant and combustion residue to exit the gun barrel but as far as I know this is limited to the specialized silent cartridges where the powder is sealed in the cartridge case after firing and a mechanical plunger or something similar is used to push the bullet down the barrel.

Cheers,
Lew