Fire Cracking and Barrel Heat

[gunsandgunsmithing]

You must be too young to be influenced by Elmer Keith! Lol

I think he played with the 41 a little bit.

I remember his articles in shooting rags but it's been a bit.

 

[DaveTooley]

Dave good information. How many barrels can you turn with a reamer?

Most calibers I rough out the chamber with a core drill. That lessons the wear on the important parts. 60 maybe as many as 80 with hss, but 80 is a stretch. They still cut pretty cleanly but a lot of my work was for people going in harms way. They deserve only the best. Carbide is the other side of 300 and even then it's cutting pretty cleanly.
I once had to trouble shoot, problem solve for an elite unit. I would have rejected every piece. Actions, barrels etc. Imagine a feather of metal coming off the trailing edge of the throat. That's the extreme but every throat cut has that to some degree. Minimizing wear is paramount for me.

 

[Wild Bill IV]

Went to the range today equipped with my new laser thermometer. Found out that the barrel temperature half way down the barrel was 20 degrees hotter then at the chamber. Why then does fire cracking appear at the chamber?

Rocket science!!!!
When you start the combustion, it takes around 1/4 to 1/3 burn of propellant to start sliding the bullet into the rifling. All the unburnt powder is forced forward!! About the time the bullet is almost in the rifling, the mass density of the retaining powder and the combined high mass gases have approached the density of fluids!! This fluid now has more power than gas power! The phase change (gas to liquid) absorbs the heat (endothermic reaction) and hydrostatic force accelerate the liquid (now a plasma) and the bullet down the barrel while pressure washing (high transport velocity) the barrel!! At a certain point, near complete burn, the volumetric increase behind the bullet reduces the density back down to gas phase chance!! At this point, heat is released (exothermic reaction), scorching the barrel, and releasing all the transport residue!!!

Isn't this combustion engine we call firearms great!!!

A quick lesson on Newton's 2nd Law, and the fundamentals (basics) of Thermodynamics and Hydrodynamics!!!

Aim small, hit BIG
BILL!!

 

[gunsandgunsmithing]

Rocket science!!!!
When you start the combustion, it takes around 1/4 to 1/3 burn of propellant to start sliding the bullet into the rifling. All the unburnt powder is forced forward!! About the time the bullet is almost in the rifling, the mass density of the retaining powder and the combined high mass gases have approached the density of fluids!! This fluid now has more power than gas power! The phase change (gas to liquid) absorbs the heat (endothermic reaction) and hydrostatic force accelerate the liquid (now a plasma) and the bullet down the barrel while pressure washing (high transport velocity) the barrel!! At a certain point, near complete burn, the volumetric increase behind the bullet reduces the density back down to gas phase chance!! At this point, heat is released (exothermic reaction), scorching the barrel, and releasing all the transport residue!!!

Isn't this combustion engine we call firearms great!!!

A quick lesson on Newton's 2nd Law, and the fundamentals (basics) of Thermodynamics and Hydrodynamics!!!

Aim small, hit BIG
BILL!!

You're obviously better versed in this subject than I but I've never heard of the combustion process of smokeless powder involving becoming a liquid. If I understand you right, you are saying it starts as a solid, turns into a gas, then a liquid and back into a gas. I've simply never seen this expressed anywhere else.

 

[TylerFromMS]

...and midway down the barrel the friction is greatest.

Do you have a source or somewhere I could learn more about this? Or is it common knowledge and I've never heard it/explanation going over my head?

 

[Wild Bill IV]

You're obviously better versed in this subject than I but I've never heard of the combustion process of smokeless powder involving becoming a liquid. If I understand you right, you are saying it starts as a solid, turns into a gas, then a liquid and back into a gas. I've simply never seen this expressed anywhere else.

Part of the solids burn to form a gas!!! That gas volume is huge compared to the volume of the solids that burnt and gas pressure spikes!!! Heat is generated from the chemical burning of the NO3 fuel which is already oxidized!! As more power burns, the mass of the gases and the remaining mass of powder squeezed forward due the parabolic internal shape of the case and the pressure, are as dense as a liquid!! But this liquid is unique!!! It absorbs the heat and is a pure high energy fluid called plasma!!! This is called the Adiabatic process in thermodynamics!! A gas/liquid phase change that absorbs heat!!! As the volume increase in the barrel/case there is a point where the plasma loses density and the plasma releases heat and returns to being a hot gas!!! The Diabatic process is the reverse of the Adiabatic process!!! Liquid to gas and releases heat!!!

I've read several reports from the 60s-80s that were releases to the public from military labs and testing field and grounds from internal ballistics studies of small firearms to the big guns!!! All stated reports identify these processes but in mathematical terms!!! Having a physics degree, I could read the language of the higher math!!! Plus, it was also mentioned in the written words!!!

By the way, the parabolic internal shape of the case is similar to the double parabolic shape of the 5 F-1 engines of the Saturn 5 1st stage rocket that sent men to the moon!!! The F-1 engines, built in the 60s, are the most powerful engines ever built by man!!! Parabola have a focal point or focus!! That shape will focus energy to a single point on the axis!!! The cartridge is a rocket engine! Not an air gun with just compressed gases!!

 

[Wild Bill IV]

Do you have a source or somewhere I could learn more about this? Or is it common knowledge and I've never heard it/explanation going over my head?

The heat from friction is distributed all along the barrel! This heat from is much, much lower than the heat generated from the combustion of the propellants!!!

 

[TylerFromMS]

The heat from friction is distributed all along the barrel! This heat from is much, much lower than the heat generated from the combustion of the propellants!!!

I can’t tell if too little or too much Adderall. Shine on you crazy diamond.

 

[6.5 forever]

I know some are confused!! A LIQUID!! Physics can be hard to understand!! A solid, to a gas, to a LIQUID, and back to a gas???
Between the Hydrodynamic and the thermodynamic of fluids, you call it a fluid if it has the properties of a fluid even though it is composed of plasma, gas, and solids!!! If that mixture flows like fluids, absorbs and emits energy like fluids, has the power of fluids, you call it a fluid!!!

If it walk like a duck, flies like a duck, quacks like a duck, you call it a duck!!!

Lets look at it from another way if you are still confused!!

States of matter are gases, liquids, plasma, or solids!! Gases are compressible! Plasma can be compressible or slightly compressible!! Liquids are slightly compressible!! Solids are not compressible!!! Therefore, the mixture falls into the liquid state!!!

Now that you know the states of matter, what state of matter would you call CEMENT?? It can be pumped!! It has to have a form!!! You can use buckets to move it!! It flows!! But when it cures (dries), it is a solid called concrete!!

When I shoot on Monday, I hope I can relax and press the trigger. I already have too many thoughts to control.

LOL

 

[Bluefink4895]

Rocket science!!!!

Part of the solids burn to form a gas!!!

WARNING
WARNING
EXCLAMATION POINT USE USE EXCEEDING SAFE LIMITS

But good stuff, never mind the impending punctuation singularity. Keep going!

 

[gunsandgunsmithing]

I know some are confused!! A LIQUID!! Physics can be hard to understand!! A solid, to a gas, to a LIQUID, and back to a gas???
Between the Hydrodynamic and the thermodynamic of fluids, you call it a fluid if it has the properties of a fluid even though it is composed of plasma, gas, and solids!!! If that mixture flows like fluids, absorbs and emits energy like fluids, has the power of fluids, you call it a fluid!!!

If it walk like a duck, flies like a duck, quacks like a duck, you call it a duck!!!

Lets look at it from another way if you are still confused!!

States of matter are gases, liquids, plasma, or solids!! Gases are compressible! Plasma can be compressible or slightly compressible!! Liquids are slightly compressible!! Solids are not compressible!!! Therefore, the mixture falls into the liquid state!!!

Now that you know the states of matter, what state of matter would you call CEMENT?? It can be pumped!! It has to have a form!!! You can use buckets to move it!! It flows!! But when it cures (dries), it is a solid called concrete!!

Why not just call plasma, plasma?

 

[Wild Bill IV]

Why not just call plasma, plasma?

The state of matter for plasma is it CAN BE compressible (low density like a gas) OR slightly compressible (high density like a fluid)!! A propane touch emits two colors of flame (visible plasma)! The yellow cooler flame is the complete burnt gases of the propane releasing heating into the air!!! The blue flame is the gases still burning absorbing that heat!! If anything is in that blue flame, that object absorbs that heat very quickly!!! That blue flame has higher mass density and holds more heat!! It acts more like a liquid! Plasma is a gas of lower energy because of it lower mass OR a liquid that hold high energy due to it high mass!! You are dealing with a gas (thermodynamics) OR a fluid (hydrodynamic) where we know the heat by measuring the temperature of the mass density!!!

 

[Larry Koch]

Here is what I know without getting to deep into the weeds. Click- bang. YMMV

 

[kapt]

Part of the solids burn to form a gas!!! That gas volume is huge compared to the volume of the solids that burnt and gas pressure spikes!!! Heat is generated from the chemical burning of the NO3 fuel which is already oxidized!! As more power burns, the mass of the gases and the remaining mass of powder squeezed forward due the parabolic internal shape of the case and the pressure, are as dense as a liquid!! But this liquid is unique!!! It absorbs the heat and is a pure high energy fluid called plasma!!! This is called the Adiabatic process in thermodynamics!! A gas/liquid phase change that absorbs heat!!! As the volume increase in the barrel/case there is a point where the plasma loses density and the plasma releases heat and returns to being a hot gas!!! The Diabatic process is the reverse of the Adiabatic process!!! Liquid to gas and releases heat!!!

I've read several reports from the 60s-80s that were releases to the public from military labs and testing field and grounds from internal ballistics studies of small firearms to the big guns!!! All stated reports identify these processes but in mathematical terms!!! Having a physics degree, I could read the language of the higher math!!! Plus, it was also mentioned in the written words!!!

By the way, the parabolic internal shape of the case is similar to the double parabolic shape of the 5 F-1 engines of the Saturn 5 1st stage rocket that sent men to the moon!!! The F-1 engines, built in the 60s, are the most powerful engines ever built by man!!! Parabola have a focal point or focus!! That shape will focus energy to a single point on the axis!!! The cartridge is a rocket engine! Not an air gun with just compressed gases!!

Way over my head....

 

[Old Navy]

I think the the forum BS meter just topped out.

 

[gunsandgunsmithing]

I think the the forum BS meter just topped out.

I think there's some good information here. What we do with it is up to us but test, and ye shall know.

 

[Wild Bill IV]

I think the the forum BS meter just topped out.

BS???? This is just one of several reports I have downloaded on Internal Ballistics!!! I'm studying all 3 fields of Ballistics to increase my knowledge and keep my brain working in my retirement!!! Open this PDF of a micro fish copy! The DDC approved stamp is on the Title page!!! Note at the bottom of the title page: US Army Aberdeen Proving Grounds, Ballistics Research Laboratories, one of many military testing grounds and fields at the time!! Scroll down in the index for the chapter titles and you will see THERMODYNAMIC!!
Look at the following Chapter titles and you will find MECHANICS and HYDRODYNAMIC!!! And yes, the density is a fluid at a certain stage!!!
If you want to see the mathematics, scroll deeper into the chapters!!!!

Some of the theory is way above my advantaged fundamental studies (BS) of these fields of study and is at the Doctoral level! I do understand and can read the language of most of the mathematical equations and understand the substitutions!! The Author gets into some Quantum mechanics!!! Way, way over my head!!!

What I've stated is what I was taught by Doctors of Science and Mathematics and have applied engineering curriculum for solution and design for 45 years!!!!

I'm looking at, will design, test, and if successful, will be applying for a couple of patents that will enhance LR precision!! There are better ways to SKIN THE CAT!!!

 

[CharlieNC]

BS???? This is just one of several reports I have downloaded on Internal Ballistics!!! I'm studying all 3 fields of Ballistics to increase my knowledge and keep my brain working in my retirement!!! Open this PDF of a micro fish copy! The DDC approved stamp is on the Title page!!! Note at the bottom of the title page: US Army Aberdeen Proving Grounds, Ballistics Research Laboratories, one of many military testing grounds and fields at the time!! Scroll down in the index for the chapter titles and you will see THERMODYNAMIC!!
Look at the following Chapter titles and you will find MECHANICS and HYDRODYNAMIC!!! And yes, the density is a fluid at a certain stage!!!
If you want to see the mathematics, scroll deeper into the chapters!!!!

Some of the theory is way above my advantaged fundamental studies (BS) of these fields of study and is at the Doctoral level! I do understand and can read the language of most of the mathematical equations and understand the substitutions!! The Author gets into some Quantum mechanics!!! Way, way over my head!!!

What I've stated is what I was taught by Doctors of Science and Mathematics and have applied engineering curriculum for solution and design for 45 years!!!!

I'm looking at, will design, test, and if successful, will be applying for a couple of patents that will enhance LR precision!! There are better ways to SKIN THE CAT!!!

An impressive report from 1942, solved with paper/pencil using a slide rule. Given numerous DoD studies over many years it's interesting not to see applications in the rifle world (vs artillery etc), as our most accurate rifles come from hands on tinkering vs an engineered design. While we still debate the existence of positive compensation, tuners, etc the technology is out there waiting to be applied!