How Does Bullet Velocity (hi/lo) Affect Barrel Wear

[ELR LVR]

Thermodynamics uses gas laws (Volume, Pressure, Heat)!! Just as I stated, powder is slightly more dense that water!! At a critical point in the burning of the powder, it acts as a fluid, not a gas!! The fluid absorbs the heat!!! Hydrodynamics take over using hydrostatic pressure to punch the bullet through the lands! As the bullet is traveling down the barrel, the volume increase and the density decrease going back to a gas and given off the heat and thermodynamics come back into play!!! Plasma is a high energy state of matter!!! Plasma gives off light energy (photons or high energy electrons). Fire gives of photons (light)!! So does the burning of powder which you don't see accept at night!! The spectrum of that light can be determined by OPTICS (the study of light)!! And, conservation of matter no long hold true due to the photons being emitted when looks at the high energy state of matter called plasma!!!

Smokeless powder fall into the explosive category!! The NO count, number of NO links or chains determines how explosive it is. The NO is an ion molecule (negatively charge). As the NO count increases per molecule, so does it explosive value(Decreasing burn time with increasing energy from larger molecular structure or mass density)! Double based powders have a small amounts of TNT which the gun cotton absorts making it stable!! TNT is the next step up with even more NO counts!! Add even more NOs, it's getting into the plastic explosives!!!

I would have to go back to the search engines to find the bunch of formulas for the internal ballistics formulas!! They will be in Calculus and Differential Equation forms and are photo copies of research papers from the 50s, 60s, and 70s!! Do you know how to read integrated and differential formulas (high level mathematics)??? You also need to be able you see the difference between thermo, hydro, and quantum formulas to understand the reports!! If you can, I will look for them!!! If you don't understand high level math, the papers will look like a foreign language to you!!!

Great Stuff Wild Bill!!!
(NG is added to the NC to make it oxygen Neutral)
And this is why I've said to people,
----Under certain conditions,
Your powder charge can transition to High Order, and no longer fall under the category of Deflagration
-------------------------------------------
Try finding the right seating depth for that load

 

[jelenko]

Thermodynamics uses gas laws (Volume, Pressure, Heat)!! Just as I stated, powder is slightly more dense that water!! At a critical point in the burning of the powder, it acts as a fluid, not a gas!! The fluid absorbs the heat!!! Hydrodynamics take over using hydrostatic pressure to punch the bullet through the lands! As the bullet is traveling down the barrel, the volume increase and the density decrease going back to a gas and given off the heat and thermodynamics come back into play!!! Plasma is a high energy state of matter!!! Plasma gives off light energy (photons or high energy electrons). Fire gives of photons (light)!! So does the burning of powder which you don't see accept at night!! The spectrum of that light can be determined by OPTICS (the study of light)!! And, conservation of matter no long hold true due to the photons being emitted when looks at the high energy state of matter called plasma!!!

Smokeless powder fall into the explosive category!! The NO count, number of NO links or chains determines how explosive it is. The NO is an ion molecule (negatively charge). As the NO count increases per molecule, so does it explosive value(Decreasing burn time with increasing energy from larger molecular structure or mass density)! Double based powders have a small amounts of TNT which the gun cotton absorts making it stable!! TNT is the next step up with even more NO counts!! Add even more NOs, it's getting into the plastic explosives!!!

I would have to go back to the search engines to find the bunch of formulas for the internal ballistics formulas!! They will be in Calculus and Differential Equation forms and are photo copies of research papers from the 50s, 60s, and 70s!! Do you know how to read integrated and differential formulas (high level mathematics)??? You also need to be able you see the difference between thermo, hydro, and quantum formulas to understand the reports!! If you can, I will look for them!!! If you don't understand high level math, the papers will look like a foreign language to you!!!

The equations for solving internal ballistics problems will not show whether the gas acts like a liquid. The properties of a gas at very high pressures [e.g. 50K psi} would simply come from experiments done on gases. Do you have a reference that simply says that the gases in a rifle at ~ 50K psi act like an liquid?

Gas laws are not related to thermodynamics. Thermo studies temperature, energy and entropy in systems. Guaranteed thermodynamics applies in all phases of internal ballistics.

 

[Wild Bill IV]

The equations for solving internal ballistics problems will not show whether the gas acts like a liquid. The properties of a gas at very high pressures [e.g. 50K psi} would simply come from experiments done on gases. Do you have a reference that simply says that the gases in a rifle at ~ 50K psi act like an liquid?

Gas laws are not related to thermodynamics. Thermo studies temperature, energy and entropy in systems. Guaranteed thermodynamics applies in all phases of internal ballistics.

Thermodynamics is the study of heat!!! Simply stated!! Gas laws do apply to thermo since heat is a function in those laws!!
1st law of thermodynamics is the conservation of heat!!
Heat is energy and measured by various types thermometers which is temperature!! EXAMPLE: Bomb calorimeters measure calories of energy keeping the system isolated from its surroundings! A calorie is the energy (heat) required to increase one gram of water one degree Celsius!! Gas laws are a part of thermodynamics whether you're looking at temperature and/or heat!!! I had the grad level thermo class!!! And studied a chapter dealing with the gas laws!!
Remember, gases are highly compressible where liquids are slightly compressible!

Now, you use your search engine and type in
Internal ballistics reports using hydrodynamics!!!!
I explained it to you!! I have done my research and study on this subject as a scientist!!!

What does the term MULTI PHASE FORM MEAN???
Gas phase to a liquid phase back to a gas phase!!!!
With the bullet being driven through the land with hydrostatic pressure, the liquid phase!!

 

[jelenko]

Now, you use your search engine and type in
Internal ballistics reports using hydrodynamics!!!!

Yeah. I did that just to see if there was any mention of using hydrostatic pressure in any of the calculations. There wasn't.

Thermodynamics is the study of heat!!! Simply stated!! Gas laws do apply to thermo since heat is a function in those laws!!

You're mixing it up. Thermodynamics is the study of energy, temperature and entropy. [Look it up].
Thermo applies to all systems, including ones that have gas in them.

 

[ELR LVR]

A quick google search show this:
Why does gas turn into liquid at high pressure if temperature is kept constant?
----------------------------------------------
Le Chatelier's principal when pressure increases - a reaction is going to shift to the side with fewer molecules of gas and eventually the gas molecules accumulate upon one another as the pressure continues to increase.

Also think about this, as an example, in the context of melting ice. The densest phase of H2O is a liquid, and when you squeeze ice you'll find that the ice begins to melt into a liquid. This is the same premise.

The more gas is compressed, the more it acts like a liquid.
---------------------------------------------
PV=nRT. R is always a constant, and you are holding T a constant
So the only way to increase P is to raise "n" (the quantity of stuff in your container) or reduce V (the volume of your container).

Either way, you are making things denser. You have more stuff per unit volume. After a while things get so crowded that the gas decides it is just easier to stick together and become a liquid instead.

----------------------
there's some trippy stuff going on in there that we just cannot monitor at every given moment.

 

[Wild Bill IV]

Yeah. I did that just to see if there was any mention of using hydrostatic pressure in any of the calculations. There wasn't.


You're mixing it up. Thermodynamics is the study of energy, temperature and entropy. [Look it up].
Thermo applies to all systems, including ones that have gas in them.

Heat is energy and temperature is a measurement of the energy (heat)!! Yes, entropy is the 2 law of thermodynamics!! I took the course 45 years ago!!
Thermodynamics is the study of heat!! SIMPLY STATED!!
We study the efficiency of various engines (2 cycle, 4 cycle and rotatory) powers by gasoline (different octane levels) and diesel by the temperature changes from the system (engine) and its surrounds!! Also studied the refrigerant cycles!! Oh, and Black body radiation!! And other systems of heat!!!

 

[ELR LVR]

Heat is energy and temperature is a measurement of the energy (heat)!! Yes, entropy is the 3 law of thermodynamics!! I took the course 45 years ago!!
Thermodynamics is the study of heat!! SIMPLY STATED!!
We study the efficiency of various engines (2 cycle, 4 cycle and rotatory) powers by gasoline (different octane levels) and diesel by the temperature changes from the system (engine) and its surrounds!! Also studied the refrigerant cycles!! Oh, and Black body radiation!! And other systems of heat!!!

Could this also be related to the fact that matter changes state to be its most efficient form within it's current environment?
This may be an OVER simplified, way of unerstanding things, however still relevent I believe
---------------
if we keep going we're going to get into Quantum Physics and how all things seek every possible path in order to travel in the shortest amount of time. Which also may be relevent but dont think we should dive into that here.

 

[Wild Bill IV]

Could this also be related to the fact that matter changes state to be its most efficient form within it's current environment?
This may be an OVER simplified, way of unerstanding things, however still relevent I believe

You're getting there!! Water at STP (stand temperature and pressure) on the earth is water!! Lower it to 0°C(32°F) it becomes a solid called ice!!! Water on Uranus cold form ice in Higher state of ice!!! If memory serves me right, there is 6 states of steam depending on the amount of heat and pressure!!! Steam, dry steam, super saturated steam to name a few!!!

 

[ELR LVR]

You're getting there!! Water at STP (stand temperature and pressure) on the earth is water!! Lower it to 0°C(32°F) it becomes a solid called ice!!! Water on Uranus cold form ice in Higher state of ice!!! If memory serves me right, there is 6 states of steam depending on the amount of heat and pressure!!! Steam, dry steam, super saturated steam to name a few!!!

Simplified ---
In order for the bullet to exit, and all things to take the fastest path from Pt A to Pt B
Given it's environmant, the gas must change state into a liquid.
Correct?

 

[Wild Bill IV]

Could this also be related to the fact that matter changes state to be its most efficient form within it's current environment?
This may be an OVER simplified, way of unerstanding things, however still relevent I believe

You're getting there!! Water at STP (stand temperature and pressure) on the earth is water!! Lower it to 0°C(32°F) it becomes a solid called ice!!! Water on Uranus cold form ice in Higher state of ice!!! If memory serves me right, there is 6 states of steam depending on the amount of heat and pressure!!! Steam, dry steam, super steam to name a few

Simplified ---
In order for the bullet to exit, and all things to take the fastest path from Pt A to Pt B
Given it's environmant, the gas must change state into a liquid.
Correct?

The gas pressure builds and the bullet is jammed up against the lands!! Gas pressure keeps building until it density is like water and hydrostatic pressure forces that bullet through the landings and down the barrel!! At a certain point down the barrel, the volume has increases enough to drop the density of the fluid back down to a gas, which sends the bullet out of the barrel!

I have seen several posts of shooters bore scoping there barrels and are puzzles by a non scorched length and then changing to scorched on out to the muzzle! The non scorched area is the fluid phase where it jet washes the barrel carrying carbon and unburnt powder!! The scorched area is the liquid phase of going back to the gas phase where carbon is deposited and heat is released!!

 

[Fire Dog]

Heat kills. That's as simple as it gets.

"SPEED" KILLS as well
However, on this subject, the more powder your burn and the faster it burns = faster throat erosion.

 

[Wild Bill IV]

A quick google search show this:
Why does gas turn into liquid at high pressure if temperature is kept constant?
----------------------------------------------
Le Chatelier's principal when pressure increases - a reaction is going to shift to the side with fewer molecules of gas and eventually the gas molecules accumulate upon one another as the pressure continues to increase.

Also think about this, as an example, in the context of melting ice. The densest phase of H2O is a liquid, and when you squeeze ice you'll find that the ice begins to melt into a liquid. This is the same premise.

The more gas is compressed, the more it acts like a liquid.
---------------------------------------------
PV=nRT. R is always a constant, and you are holding T a constant
So the only way to increase P is to raise "n" (the quantity of stuff in your container) or reduce V (the volume of your container).

Either way, you are making things denser. You have more stuff per unit volume. After a while things get so crowded that the gas decides it is just easier to stick together and become a liquid instead.

----------------------
there's some trippy stuff going on in there that we just cannot monitor at every given moment.

At a certain point in the density build up, it acts like a fluid!! The gas is exothermic meaning heat is being released or temperature and pressure is rising!! At the liquid phase, it is endothermic, meaning it is absorbing the heat and temperature hangs with powder still gasing off behind the fluid column!! Temperature changes fluctuate as the pressure build!! If there was not phase change, that barrel would heat up really fast if fluid dynamics didn't exist!!

 

[ELR LVR]

I have seen several posts of shooters bore scoping there barrels and are puzzles by a non scorched length and then changing to scorched on out to the muzzle! The non scorched area is the fluid phase where it jet washes the barrel carrying carbon and unburnt powder!! The scorched area is the liquid phase of going back to the gas phase where carbon is deposited and heat is released!!

Very cool !!! thank you,
I've heard/read that the bullet starts to move a certain distance, then stops,
then gets moving again, and then the jacket itself turns liquid on its surface, which facilitates its movement to continue for the rest of its travel.
An area of unschorched portion of the barrel further out/ where the fluid phase is occuring seems to fall in line with this...
starting and stopping of the bullet / areas of transitions from gas to fluid

 

[Wild Bill IV]

"SPEED" KILLS as well
However, on this subject, the more powder your burn and the faster it burns = faster throat erosion.

Speed is a factor of the pressure and heat!! The more powder you burn is directly correlated to the increase of pressure and heat!! More powder = More speed = more pressure = more heat!! Anyway you say it, it is all the same!
More speed burns the barrel!!!!
More pressure burns the barrel!
More powder burns the barrel!!
More heat burns the barrel!!

 

[SteveOak]

I do not lament the eternal loss of the bullet I just launched at the target, nor the powder that was consumed in doing so, nor the irreparable harm done to the primer as they, along with the barrel, are all consumables, sacrificed in the pursuit of the enjoyment I derive from shooting.

 

[urbanrifleman]

One of the store motto of the Urbanrifleman is "barrels is like Doritos.... Shoot all you want, I'll make more."

Life is short. If you want to go shoot a lot, my nut barrel is $320. You don't have to get married to it.

 

[jelenko]

Ok. One last attempt.

Here's the three laws of thermodynamics: Note - it's not just about heat.

1st: In a closed system (i.e. there is no transfer of matter into or out of the system), the first law states that the change in internal energy of the system (ΔUsystem) is equal to the difference between the heat supplied to the system (Q) and the work (W) done by the system on its surroundings.

Note: Heat is only one form of energy and Work is done without the application of Heat.​

2nd: When two initially isolated systems in separate but nearby regions of space, each in thermodynamic equilibrium with itself but not necessarily with each other, are then allowed to interact, they will eventually reach a mutual thermodynamic equilibrium. The sum of the entropies of the initially isolated systems is less than or equal to the total entropy of the final combination. Equality occurs just when the two original systems have all their respective intensive variables (temperature, pressure) equal; then the final system also has the same values.

Note: Other intensive variables include concentration, mole fraction, mass fraction, specific heat capacity, color, chemical potential, charge density, energy density, magnetic permeability, and melting point and boiling point. I.e., none are 'heat'.​

3rd: A system's entropy approaches a constant value as its temperature approaches absolute zero.

 

[FNSafari]

Barrel wear is primarily the result of gas cutting the bore. Its been understood for a long time. Barrel wear is not significantly caused by the projectile, affected yes, but not a major cause. Think overbore cartridges like the 220 Swift, most "magnum" cases, the RUMs, WSSMs, Rem ultra mags. All that powder burning in the tube is the real culprit.

 

[SGT. Slaughter]

With my 30BR and 6 PPC, the only appreciable “wear” is the area just forward of the throat.

I set them back periodically and they keep shooting.

When you say periodically is that a certain round count or does it depend on the wear of the throat? If it's round count how many rounds when you decide to set it back on the 6ppc and how many on the 30br? Thanks.