Does a shorter barrel cool off faster?

haldir

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Does a shorter barrel cool off faster? I was doing some rapid firing with my .308 which has a 20" heavy barrel and noticed that it seemed to cool off rather fast, thanks.
 

hunter223

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Re: Does a shorter barrel cool faster?

It should, less material to cool down. Should heat up faster too.
 

Black-X

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Re: Does a shorter barrel cool faster?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">Length has less to do with it than total mass. </div></div>

And surface area.

-X
 

haldir

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Re: Does a shorter barrel cool off faster?

So what I'm getting is that a short, heavy barrel which has less material and more surface area will cool off faster, than a longer thinner or heavy barrel?
 

EventHorizon

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Re: Does a shorter barrel cool off faster?

No. A shorter barrel of the same calibre cannot have more surface area unless it has a much larger circumference. Also two barrels of equal length and uniform contour but different thickness will see the thicker one take longer to get hot and probably longer to cool down hence why homes with thicker walls tend to be cooler in the summer and warmer in the winter - less heat transference.
 

chops_are_in

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Re: Does a shorter barrel cool off faster?

In my experience thicker barrels take longer to heat up and longer to cool down. I've never noticed a heat soak difference in barrel lengths.

In order to cool the barrel even faster, I insert a 32" section of 0.200" aluminum rod that has been deburred into the bore with the action open. It works!

Chops
 

haldir

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Re: Does a shorter barrel cool off faster?

So fluting will help it cool faster?
 

jrpilot

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Re: Does a shorter barrel cool off faster?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: haldir</div><div class="ubbcode-body">So fluting will help it cool faster? </div></div>

Fluting will help a barrel cool faster. It gives it more surface area.
 

ainnamor

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Re: Does a shorter barrel cool off faster?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: haldir</div><div class="ubbcode-body">So fluting will help it cool faster? </div></div>

Yes, depending on the flute profile. The flutes have to increase surface area, not just look cool. The barrel will also heat up faster then a barrel of the same profile and length but without flutes.
 

haldir

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Re: Does a shorter barrel cool off faster?

Which is better, a barrel that takes longer to heat up, or a barrel that cools faster? What barrel will give me both? What powder will keep my .308 barrel cooler?

Thanks.
 

lowlight

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    Re: Does a shorter barrel cool off faster?

    Who cares... you guys are barking up the wrong tree with heat, especially with the 308.

    <object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/3UZ-mApuUoM"></param> <param name="wmode" value="transparent"></param> <embed src="http://www.youtube.com/v/3UZ-mApuUoM" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object>
     

    patches

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    Re: Does a shorter barrel cool off faster?

    "In a minute we are going to shoot our fuckin' 20 rounds."

    Victor is gonna get you.....

    Camera work that deserves a daytime Emmy too.

    None the less, good video and it definitely proves a point!
     

    lowlight

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    Re: Does a shorter barrel cool off faster?

    We are bad influences on each other when George is around I tend to swear more than usual... however by most people's standards I swear a lot to begin with.
     

    Iloveguns

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    Re: Does a shorter barrel cool off faster?

    Never since the Days of "Apocalypse Now" or "Glory" have I seen such artistry through the camera lens!! Love the vid and the fucks!!
     

    error4o4

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    Re: Does a shorter barrel cool off faster?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: haldir</div><div class="ubbcode-body">Does a shorter barrel cool off faster? I was doing some rapid firing with my .308 which has a 20" heavy barrel and noticed that it seemed to cool off rather fast, thanks. </div></div>

    From a physics standpoint, if all other variables are the same, the shorter barrel will cool faster. It has nothing to do with length, but everything do do with mass and surface area.
     

    TheShooter

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    Re: Does a shorter barrel cool off faster?

    Pretty sure that the ratio of mass to surface area is the same for a long and short barrel of the same diameter.
     

    BruxBarrels

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    Re: Does a shorter barrel cool off faster?

    Just some food for thought. Barrel life greatly depends on the amount of rounds through the barrel in a certain amount of time. Here in the USA the average Palma rifle barrel will last 3000-4500 rounds. In other countries, the average palma/fullbore barrel will last up to 8000 rounds. This is because in the US our course of fire is different and we shoot more rounds in a shorter time frame(1 round every 45-90 seconds up to 25 rounds) where as in other countries they shoot less rounds in a longer time(1 round every 120-180 seconds generally up to 17 rounds).

    This process of firing greatly extends the barrel life as it doesnt heat up as much, causes less wear and throat erosion.
     

    lowlight

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    Re: Does a shorter barrel cool off faster?

    Respectfully,

    I'm not buying that is the reason. I would bet it has more to do with US perceptions over European. We are much more likely to change things out "because" and not because of a quantifiable number like, the barrel needing changing.

    My last barrel change I did at 12,000 rounds and according to GAP could have went farther, I really only changed it because. The rifle before that went to 15,000+ and we shoot the snot of out them, without any regards to time limits.

    It's like bench resters who change their barrels whenever they get any spare change in their pocket.

    I bet Europeaners are just not as cavalier about it. If you are saying 10 rounds and 1 minute per competition yard line are reducing your life by 1/2 -- those must be sandpaper bullets being shot here in the US.
     

    callen3615

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    Re: Does a shorter barrel cool faster?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">Length has less to do with it than total mass. </div></div>

    Thats what she said.
     

    Graham

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    Re: Does a shorter barrel cool off faster?

    It would make sense that the throat, which is what wears out, gets rougher and wider in diameter as it erodes. It would follow that a bullet with a large bearing surface (unlike a Palma bullet) will shoot better in a worn barrel because it has a larger length of corresponding diameter. Maybe that's why 'our' and 'tactical' barrels shoot better for longer periods of time.

    But the etching on the throat from the hot gasses is caused primarily by the heat and pressure at the peak of the pressure/time curve. And this is flame, not just heat. So, I would think that the barrel would cool sufficiently from this peak even during rapid-fire strings. Thus, retained heat can't be much of a factor in barrel wear.

    Theoretically there might be more gas leakage in a hot barrel, which might contribute to a higher erosion rate at the p/t peak, but it can't be that much when compared to the longer time a heavier bullet spends in the thoat, with more powder behind it, at the p/t peak.
     

    border_reiver

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    Re: Does a shorter barrel cool off faster?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Respectfully,

    I'm not buying that is the reason. I would bet it has more to do with US perceptions over European. We are much more likely to change things out "because" and not because of a quantifiable number like, the barrel needing changing.

    My last barrel change I did at 12,000 rounds and according to GAP could have went farther, I really only changed it because. The rifle before that went to 15,000+ and we shoot the snot of out them, without any regards to time limits.

    It's like bench resters who change their barrels whenever they get any spare change in their pocket.

    I bet Europeaners are just not as cavalier about it. If you are saying 10 rounds and 1 minute per competition yard line are reducing your life by 1/2 -- those must be sandpaper bullets being shot here in the US. </div></div>

    The saying, your mileage may vary, applies to this a bit. Depends on the application. Frank, Brux is pretty much on the money. Euros use same cartridge components we do, but in the Palma example, the factor is time. Time can work for you and against you when barrel erosion and barrel wear take hold. Full auto before plastic deformation actually does less goofy things to the throat than slow fire bolt. I've seen a bolt action 260 cooked out in less than 1000, in a weekend, due to the barrel temps, and the changes going on in that bore surface due to the conditions of fire and ambient temp..

    JR
     

    3PER

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    Re: Does a shorter barrel cool off faster?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Who cares... you guys are barking up the wrong tree with heat, especially with the 308.

    <object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/3UZ-mApuUoM"></param> <param name="wmode" value="transparent"></param> <embed src="http://www.youtube.com/v/3UZ-mApuUoM" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object> </div></div>


    So, Frank, as I understand it, you are saying I should stop worrying about barrel heat and just shoot?
    (700 Milspec 5R) Chances are I will never put 15000 rounds down it anyway.
     

    Elxx

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    Re: Does a shorter barrel cool off faster?

    Think of it this way, have you ever seen an increase in group size after shooting 10 rounds in rapid succession? Doubtful.

    I know the OP was just asking a general question, but this is directed towards the average SH member. Quit fucking worrying about all this little shit.

    Go outside. Hit some X's and move on.

    Edit: Watched LowLights video. Proved my top point, and my last. =)