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Posted: 3/14/2011 4:48:20 PM EDT
[#1]
I would think the hot gasses and pressure from it account for most of the heat...
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Posted: 3/14/2011 5:18:11 PM EDT
[#2]
I couldn't figure out how much but I'd say the major percentage would be from friction. Think about it, the burning propellant in the barrel is only there for a fraction of a second. For a fraction of a second you could pinch a candle and put it out without burning your fingers. But say take your finger and touch a car tire that is going 50 miles per hour and you'll burn instantly. I know it's not an apple to apple comparison but you get the picture.
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Posted: 3/14/2011 5:51:52 PM EDT
[#3]
i'd say both, but mostly from hot gas.
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Posted: 3/14/2011 5:52:26 PM EDT
[#4]
I've been told it's the friction that accounts for most of it.
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Posted: 3/14/2011 5:57:15 PM EDT
[#5]
I'm voting for the 50,000 psi scorching hot gasses personally. Think about how hot a piece of brass is immediatly after ejection even from a cold chamber. It certainly isn't hot from friction. THat hot gass rushing down the barrel may only be there for a fraction of a second, but it is at extraordinarily high pressure and that makes a big difference.
Adrock1 |
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Posted: 3/14/2011 5:59:13 PM EDT
[#6]
Gas cutting like a torch. If it were friction, it would be higher toward the muzzle. The barrel wears from the throat.
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Posted: 3/14/2011 6:44:12 PM EDT
[#7]
Quoted:
I couldn't figure out how much but I'd say the major percentage would be from friction. Think about it, the burning propellant in the barrel is only there for a fraction of a second. For a fraction of a second you could pinch a candle and put it out without burning your fingers. But say take your finger and touch a car tire that is going 50 miles per hour and you'll burn instantly. I know it's not an apple to apple comparison but you get the picture. Candles don't explode with vicious force. |
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Posted: 3/14/2011 6:49:36 PM EDT
[#8]
Friction guys ..... |
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Posted: 3/14/2011 6:56:18 PM EDT
[#9]
So, does friction cause gas port erosion too?
Gas checking or gas cutting. Crappy pic showing gas port erosion: 
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Posted: 3/14/2011 6:56:34 PM EDT
[#10]
Quoted:
Gas cutting like a torch. If it were friction, it would be higher toward the muzzle. The barrel wears from the throat. Agree |
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Posted: 3/14/2011 6:58:48 PM EDT
[#11]
I searched around and found my answer from some government tests on the .30-06:
ENERGY CONSUMED IN FIRING EventCaloriesPercent heat to cartridge case 131.0 calories 4.26 % kinetic energy of bullet 885.3 calories 28.78 % kinetic energy of gases 569.1 calories 18.50 % heat to barrel 679.9 calories 22.10 % heat to gases 598.6 calories 19.46 % heat generated by friction 212.0 calories 6.89 % Total3075.9 calories so the ratio of gas to friction heating of the barrel is: 3.2. |
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Posted: 3/14/2011 7:21:43 PM EDT
[#12]
Quoted:
So, does friction cause gas port erosion too? Gas checking or gas cutting. Crappy pic showing gas port erosion: http://www.ar15barrels.com/tech/gas-port-erosion.jpg Crappy or not. That is a great image |
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Posted: 3/15/2011 6:03:57 AM EDT
[#13]
Quoted:
So, does friction cause gas port erosion too? Gas checking or gas cutting. Crappy pic showing gas port erosion: http://www.ar15barrels.com/tech/gas-port-erosion.jpg There is something wrong with this picture. Gas port erosion usually creates an hour glass pattern as the gas port erodes. The barrel in the picture looks like it would have been ripping the jackets off the projectile... |
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Posted: 3/15/2011 12:57:31 PM EDT
[#14]
Shotgun barrels get extremely hot, and I would presume a plastic wad to go down a smoothbore barrel with less friction than a copper-jacketed bullet through a rifled barrel.
So I'll go with hot gasses. |
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Posted: 3/15/2011 1:44:54 PM EDT
[#15]
Quoted:
Shotgun barrels get extremely hot, and I would presume a plastic wad to go down a smoothbore barrel with less friction than a copper-jacketed bullet through a rifled barrel. So I'll go with hot gasses. winner good point. |
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Posted: 3/15/2011 1:54:05 PM EDT
[#16]
Global Warming.
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Posted: 3/15/2011 2:10:48 PM EDT
[#17]
How hot do barrels get when firing blanks?
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Posted: 3/15/2011 3:03:09 PM EDT
[#18]
Ask Al Pachino when he was filming, "Scarface".
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