Barrel Temp Outside/Inside -- What Is Too Hot?

[Curmudgeon]

I see a temp for outside barrel temp, 125 F guideline, has been mentioned. When temping toward the crown does barrel dimension matter? What could the bore temp be from leade and then down the barrel ? At what internal temp does damage begin? Does this matter or should we be content with external temperature? Thanks

 

[6.5 forever]

Good question. Following.

 

[rickt300]

I say 125 degrees F is far too low. Especially for say a 308.

 

[stavey]

When I bought my MPA BA rifle it came with a temp strip on the barrel. This is what the owners manual says. I’m not saying this is rite or wrong . This is Masterpiece arms stance on the issue.

 

[SG4247]

I use the barrel cooler when the outside of the barrel near the chamber, reaches 140F.

 

[SG4247]

BTW, 140F is about as hot as you can stand to touch for more than a few seconds with your fingers. So a temp strip or pyrometer is not really needed. Just reach up and carefully touch the barrel in front of the chamber.

If it burns your fingers quickly, you should stop and let the barrel cool, or use the barrel cooler. I do this in fclass competition today. Works well.

I dont care about the temperature elsewhere on the barrel because the heat cracks seen with the borescope, usually form at the first 0”-6” just in front of the chamber.

 

[SKWERLZ]

BTW, 140F is about as hot as you can stand to touch for more than a few seconds with your fingers. So a temp strip or pyrometer is not really needed. Just reach up and carefully touch the barrel in front of the chamber.

If it burns your fingers quickly, you should stop and let the barrel cool, or use the barrel cooler. I do this in fclass competition today. Works well.

I dont care about the temperature elsewhere on the barrel because the heat cracks seen with the borescope, usually form at the first 0”-6” just in front of the chamber.

This is what I do.

 

[gunsandgunsmithing]

Lets face it...shootings guns is hard on barrels! Lol! It's also hard on our supply of bullets, brass, primers and powder. Enjoy them all while they last and buy more!

 

[BowWow]

On a hot summer day, just leave the rifle out in the sun. The outside of the barrel can easily be 120 unfired. Maybe more in the southwest.

 

[D-4297]

Let's see ....Arizona Summer ambient temp at Ben Avery , on the shooting Mat can reach 145 degrees by mid-morning . That's around 9:30 - 10:00 A.M. , so if you leave your rifle sitting on the Mat , uncovered for any length of time , you could be approaching the Danger Zone before ever firing a round . Most shooters out here cover their Barrels with a towel , or some other covering , not only to keep the Sun off , but also the Arizona micro-dust , which is just as damaging to every part of the rifle .

 

[dcali]

I have a hard time believing it matters much. My barrels have always shot well regardless of their temperature (within reasonable limits, obviously, but 30 shot f class strings aren't an issue). And I don't think that the barrel is going wear materially more if it's hot - the gases are already in thousands of degrees. What's another 100 going to matter?

I would be curious to know the inside vs outside temps. Surely someone has measured this. The outside is going to lag significantly behind the inside and never reach the same heights as the throat.

 

[chop house]

I would be curious to know the inside vs outside temps. Surely someone has measured this.

pretty sure you can get close with a back of the envelop calc. but then again, thermodynamics was not my strongest undergrad course.

 

[DogBuster]

Iffin your Cham Wow is steamin' in the p/dog fields

Either switch rifles or take a break

Although......they build barrels everyday......

 

[SG4247]

Made an A in thermodynamics, and fix F22 Raptor engines for a living.

Any opportunity to keep bbl temperature at stable, but reasonable temperature, is a good thing. Not only for bbl life, but for accuracy too.

My BAT single feed actions won’t hardly open or close, if the chamber gets really hot . Why is that?

My AR steel plate guns run 20 rounds in 20-25 seconds in rapid fire - after - they have shot 25 or so in non timed short range. So, 45 rounds in say two min. I have burned out a few….

The barrel cooler, towels all that help significantly.

Avoid wet towels on a hot barrel, tried that at a match once, and clearly lost points because of it.

Or you can just shoot!

 

[DogBuster]

Made an A in thermodynamics, and fix F22 Raptor engines for a living.

Any opportunity to keep bbl temperature at stable, but reasonable temperature, is a good thing. Not only for bbl life, but for accuracy too.

My BAT single feed actions won’t hardly open or close, if the chamber gets really hot . Why is that?

My AR steel plate guns run 20 rounds in 20-25 seconds in rapid fire - after - they have shot 25 or so in non timed short range. So, 45 rounds in say two min. I have burned out a few….

The barrel cooler, towels all that help significantly.

Avoid wet towels on a hot barrel, tried that at a match once, and clearly lost points because of it.

Or you can just shoot!

Shootin p/dogs

Not points........

 

[SG4247]

Shootin p/dogs

Not points........

You shooting Pdogs with 55 grains of H4831SC?

Not shootin .17s or 22s either!

 

[jelenko]

Made an A in thermodynamics, and fix F22 Raptor engines for a living.

 

[SG4247]

So it all boils down to energy and time. Like most things in life ironically. I dont have much of either.

Heat is energy - that energy comes from gunpowder being converted.

So, energy converted over time, is what we all have deal with in rifle bbls.

You can think of it as lbs of fuel converted per min.

A Small case cartridge being fired many times in a given time period, can be equal in heat output to a larger case cartridge being fired less times in the same given time period.

Ever wondered why the mechanic says the heads are cracked on the family car? Heat cycles and the surrounding material properties. Just like rifle barrels.

The question is, what to do about it? Water cooling, nitrogen, air boundaries, coatings, fuel chemistry, air coolers, barrel materials, etc..

Or just shoot it, and screw on a new one when needed. But it is hard to live with 800-1000 rnds of bbl life if you shoot a bunch. Unfortunately, I dont think the barrel makers are too worried about this at the moment.

 

[dcali]

Made an A in thermodynamics, and fix F22 Raptor engines for a living.

Any opportunity to keep bbl temperature at stable, but reasonable temperature, is a good thing. Not only for bbl life, but for accuracy too.

My BAT single feed actions won’t hardly open or close, if the chamber gets really hot . Why is that?

My AR steel plate guns run 20 rounds in 20-25 seconds in rapid fire - after - they have shot 25 or so in non timed short range. So, 45 rounds in say two min. I have burned out a few….

The barrel cooler, towels all that help significantly.

Avoid wet towels on a hot barrel, tried that at a match once, and clearly lost points because of it.

Or you can just shoot!

Your Bats shouldn't be doing that. I think you've got another problem.

 

[Curmudgeon]

Shot a long range bench match in Tucson in summer with my 300 rum, used a wet towel in attempt to cool barrel. Towel slipped and covered brake. Ha Ha , confetti everywhere, shooting friends said don’t worry, he’s from California. I’d like to score my sighters and not match string. Barrel was hot without firing single shot. Guess we’ll just continue to keep our smiths in business. Way better than video games. Cheers