Cooling hot barrel

[Syncrowave]

Quote from same article: " ...powder burns at about 5,000' -5,500'F. for about a millisecond, and the metal at the bore surface in the throat region is heated about that hot only to a very shallow depth- perhaps a ten-thousandths at most.

Steel boils at about 5,200° F. So is this guy claiming that a tenth of steel gets vaporized with every shot? That should wash out a barrel with – what? – about 15 shots?

 

[Syncrowave]

All joking aside what is the flash point of these gun oils? Does that point change with more oxygen?

Put some oil into an oxygen regulator and then open the valve and find out!

 

[Tim Singleton]

Oxygen tanks are pressurized at 4000 to 5000 psi then into a flow regulator to be used at a lower pressure. If oil is inside this high pressure regulator then it's a problem.

Comparing oxygen blown at low pressure into a barrel thinking it will flash would be the same as saying every machinist or mechanic in the world who uses an air hose to blow away oily chips or oily parts are at risk of explosion.
Is that what is being said?

 

[LHSmith]

[


Steel boils at about 5,200° F. So is this guy claiming that a tenth of steel gets vaporized with every shot? That should wash out a barrel with – what? – about 15 shots?

"Steel boils at about 5,200 'F" is your own interpretation. ....not what I quoted. Did you read the next few sentences in my post ......about the nitriding layers causing a thermal gradient? "This guy" WAS a metallurgist and if you google "Fred Barker - Precision Shooting" it appears his opinion was highly valued among competitive shooters.

 

[LHSmith]

Oxygen tanks are pressurized at 4000 to 5000 psi then into a flow regulator to be used at a lower pressure. If oil is inside this high pressure regulator then it's a problem.

Comparing oxygen blown at low pressure into a barrel thinking it will flash would be the same as saying every machinist or mechanic in the world who uses an air hose to blow away oily chips or oily parts are at risk of explosion.
Is that what is being said?

The difference between compressed air ( 20% O2) and compressed O2 (100 % O2) is concentration.....from what I recall in safety meetings from previous work with a company that operates air separation plants throughout the globe: That which burns in air will burn much more readily in an enriched Oxygen environment. I dealt with hospital gas piping distrubution systems, O2 ( medical grade from cylinders) was one of the gasses piped throughout the hospital @ 50 psi delivered at the outlet.....all components including the type k copper distribution lines and valves had to be degreased with a solution of tri-sodium-phosphate to ensure removal of all oils for the reason of the violent reaction of pressurized O2 and grease.
Just not a good practice to use pressurized O2 where compressed air will accomplish the same.

 

[Tim Singleton]

I am med gas certified. Although it's been a while.
I definitely agree compressed air is the way to go. Not compressed oxygen.
I was just making the point that an oxygen enriched environment still needs the flame or spark to become dangerous.

I have seen horrible pics of people trying to smoke a cigarette with an oxygen tube in their nose. Bad facial burns. The oxygen tanks are best left alone

 

[LHSmith]

^^^^^ It is my understanding that under certain circumstances combustion with oils can begin without a spark due to rapid oxidation...causing heat build up....think of the spontaneous combustion due to oily rags.

 

[Tim Singleton]

When oxygen is under high pressure. That is the qualifier.
An Enriched oxygen environment at low pressure is an accelerant but does not cause combustion.
Oxygen under high pressure where friction can occur over say oil or grease then it is a problem

http://miningquiz.com/pdf/Hazardous_Materials/DON'T_MIX_OXYGEN_AND_OIL.pdf

 

[LHSmith]

^^^^^I am glad we agree to agree on the hijacked point of this thread.

 

[people]

When oxygen is under high pressure. That is the qualifier.
An Enriched oxygen environment at low pressure is an accelerant but does not cause combustion.
Oxygen under high pressure where friction can occur over say oil or grease then it is a problem

http://miningquiz.com/pdf/Hazardous_Materials/DON'T_MIX_OXYGEN_AND_OIL.pdf

That is good info.

 

[DogBuster]

you guys get to technical.......throw a wet rag on it & shoot dogs...

>>>>>>>>>>>>>>>>> ;D<<<<<<<<<<<<<<<<<<

 

[mikegaiz]

So dose rapid cooling hurt the barrel????

 

[LHSmith]

So dose rapid cooling hurt the barrel????

Did you read posts 39 and 42? Almost all the replies were "how" they cooled the barrel, a few claimed they saw no harm in rapid cooling , and a metallurgist familiar with firearms claims it shortens barrels life. Choose who you want to believe. I'm in Fred Barkers camp as his explanation is plausible and mirrors what I have observed.

 

[XTR]

There is a not so funny story in Oak Ridge of a guy working in one of the shops there who shut down his torch and used the O2 to blow inside is coveralls to cool down, then walked out to have a smoke. The safety incident report reads "burns to the areas below his waste" .

I'd leave the O2 to the cutting and the medical applications.

 

[mikegaiz]

I am trying to learn about this, and my understanding of rapid cooling may differ. A blast of Co2 (below freezing) in the bore and applying coolant that is cold around 32* to the outside of the barrel will not cool the inside so fast, or maybe that is too fast as well. It would be slower than hunting rifle cools in 0 temperatures on the barrel. I Know quenching really hot (glowing) steal will harden and possibly crack steel, but quenching is part of the process for good steel. leaves me with questions??????? The only experience I have is shooting 6.5/284 during load development I cooled with Ice and the three I did that on, accuracy dropped off around 1200 rounds, which I think is the same as others have found.

 

[LHSmith]

You asked if any harm can be done rapid cooling barrels.....I gave info from a credible source that in his educated opinion the answer is "yes" and explained the science behind his reasoning. Using his advice may not be workable in match situations and in some barrels will be detrimental to accuracy. The trick is to find a happy medium to net good accuracy along with longer barrel life.
Again, just like fouling, a barrel must be brought to a certain temp. before it reaches it's accuracy level....the colder you make the barrel in attempts to remove barrel heat, it will require that many more rounds to bring it up to the temp. where it starts to perform.....more rounds = more erosion why is that so hard to understand?

 

[hogan]

Ain't No Such Thing As Free Lunch...


Metallurgy of steel suggests that any rapid cooling cycle will have detrimental effects, unless the steel ain't formulated in manner of Good Barrel Stock...

Might look at machinegun barrels, and small bore cannon barrels; they're designed to take the heat, but only for so many rounds, and accuracy is for sure NOT a concern... beyond MOA of man or MIG.


Oil bath is pretty decent means to remove excess heat w/o making molecules brittle.

Sure that fluting and bead-dimpling have been mentioned for ways to increase radiant area beyond typical barrel cylinder dimension. Big radiant improvements there... No free lunches served.... Even watercooled machineguns boil their waterjacket contents away...

Friction yields heat. An intrinsic physical phenomenon of shooting. Friction and powder ignition... Aside from using a rifle barrel as a heat generation device, like a heat sink for a heat pump, not much can do to remove heat from the effected surface.


Even pellet and bb guns make heat if get enough projectiles routed through barrel in short time.


Maybe "smart bullets" that function like tiny cruise missiles will do away with need for rifling and barrel pressures? Military figures 200K rds to kill an enemy? Maybe a $1000 bullet isn't a bad deal after all if guided onto target???


Don't get a barrel "hot" in the first place, if you value its precision capability....

 

[BoydAllen]

One of the tricky things in this is that it take a while for the outside of a heavy barrel to heat up, and that can fool you into using a rate of fire that can hurt your barrel even though the outside never got excessively hot to the touch.

 

[JRS]

One of the tricky things in this is that it take a while for the outside of a heavy barrel to heat up, and that can fool you into using a rate of fire that can hurt your barrel even though the outside never got excessively hot to the touch.

Right again, Boyd If the outside of the barrel has reached 140, or so degrees…. what is the temperature inside that barrel ??? The temperature on the outside of the barrel means essentially, nothing. Of course, unless it is a #3 or #4 weight barrel.

 

[slm9s]

I once acquired a browning BAR in 338wm a couple weeks before elk season. I had limited range time and that sporter barrel heated up quick. I had a small D-cell powered camping mattress pump already. $1 for a foot of surgical tubing at the hardware store. Rifle in the rack vertical, surgical tubing over muzzle, turn on the pump and the rifle cooled in roughly 50% of the time.

It worked well, but I got some strange looks from the guys at the range. 8)