Damaging barrel with heat

[nords]

G'day,

This is just to answer some thoughts turning over in the old noggin.

Without deliberately being stupid, do you think it's really possible to damage a rifle barrel with heat.

Just a bolt action, not a belt fed machine gun.

Stitching bits of information together here... When you anneal brass it has to be near glowing which is hundreds of degrees before it softens, right?

Coming back to the belt fed machine gun, the army and whoever use these things to pump out more rounds than you could ever get even remotely close to with a bolt action. Not even comparable really, and they still obviously work.

So can you really get a bolt action barrel hot enough to damage it from firing away at modest speed at the range?

[Vati]

My 2 cents. I shoot until the barrel too hot that you have to recoil your hand if you touch it.

Hardly scientific but that's what I've always done and have not experienced any problems long term with my rifles.

[Baldrick314]

I don't think you can damage a barrel from it being too hot. It could accelerate barrel wear by heating up an already high power load to cause extra pressure but you'd be hard press to fire enough rounds fast enough to heat the barrel up to the point of damaging the steel

[pajamatime]

maybe you should ask the Americans lol

[DaleH]

too hot to touch is ~ 65C. Boiling water is 100C. Steel heat treatment / annealing is + 500C. I would say that your stock would cook, your scope melt, your rounds cook off and you would receive serious burns cycling the bolt before you effected the steel

[RealNick]

maybe you should ask the Americans lol

Yeah, need some faster cycling toys like the Mericans to do it I reckon.

[nords]

Thanks for the numbers Dale.

I think you're right... A nice slaggy puddle of rubber where your butt pad used to be is likely

[Harper]

I think you'd be seeing waves of heat coming off the thing into the air before you did any damage.

You'd have to be doing it deliberately I reckon?

[DaleH]

Story from my Dad during National service many moons ago dealing with the firing of a Bren gun.

After a couple of mags in rapid succession, it was necessary to change out the barrel (the Bren was set up with a quick change facility and the gunners off-siders job was to carry the mags and spare barrel apparently).

The barrels were too hot to touch and needed gloves to change them out.

They were cooled with water and re-used. If the quick cooling with water wasnt enough to damage them, then they certainly were not hot enough for the steel to be damaged.

[Monty]

I think you'd be seeing waves of heat coming off the thing into the air before you did any damage.

On a still day with a low mounted scope you often can see this coming off the barrel.

[tom604]

talk to your dad again i think you will find they used to pee on them as well

[Aster]

More than that... They had reservoir based cooling systems filled with whizz

Things like the Browning M1917.

Not many fresh streams running through the trenches

Gotta fill those containers somehow...

[Warrigul]

On a still day with a low mounted scope you often can see this coming off the barrel.

On my Omark I have a seatbelt strap with a spring at either end running from the front sight to the front mount of the scope simply to combat barrel heat sight distortion on a still day.

Back when I was using apeture sights still I originally thought that my eyes were going "off" after five or six shots, it was just the heat rising off the barrel and the problem was eliminated once I fitted the strap.

Works a treat.

[DaleH]

OK guys, you caught me out - pee was the readily available cooling fluid - water was a luxury.
Please note to all - I do not recommend doing this to your Sako, CZ or any other during a shoot at your local range......

[Chronos]

i think we're forgetting the intense heat that occurs in the throat just in front of the chamber, this area is exposed to the most combustion heat and this is where you can cause damage with repeated firing, infact this is where 90% of all barrel wear occurs

when you fire a round through a cold barrel an amount of heat is transferred to the barrel from the inside out, the barrel then starts to cool, another shot is fired, more heat is added to the residual heat in the barrel, possibly before the barrel has reached uniform temp making the difference between the bore and the rest of the barrel. the more metal there is to heat up the slower the bore will heat up and the slower it will cool down making the transfer of heat more even and helping keep accuracy longer in rapid shooting

before long the bore is scorching hot but the outside of the barrel is just warm to touch. it's this temperature difference that causes damage. heat cracking or fire cracking (aka known as alligator skin or scaling) is seen in the throat on rifles exposed to fast fire sessions like service rifles and extreamly flat shooting varmint rifles like the american prairie dog guns which can practically destroy a barrel in a few days shooting



http://bulletin.accurateshooter.com/tag/heat/

Chronos

[pajamatime]

Yeah, need some faster cycling toys like the Mericans to do it I reckon.

yeah they got access to the stuff that can generate allot of heat in a shorter amount of time where is what they can do in 30 mins or less we would probably be there for hours trying to accomplish with our bolt action XD

[Grated]

I note it says hard barrel use without cleaning.

I wonder how it compares on clean barrels?

[Chronos]

If you follow the link to the article you'll read they shot two identical barrels for 300 rounds. One slow fired and cleaned every 50 rounds, the other rapid fired in 20 round bursts and only cleaned every 100 rounds

Chronos

[reddog]

http://www.youtube.com/watch?v=syyYCv8M3-E
I think this is a little hot
On the last mag it cooks off

[Grated]

Ah, soz I didn't read that far.

Just assumed from the snippet with the photo.

[Grated]

http://www.youtube.com/watch?v=syyYCv8M3-E

What a moron...