Cooling hot barrel

[Ackman]

Gun goes off and throat temps are instantaneously what, something like 3500*? That's pretty extreme. Cooling from 130/140/150 to ambient temp is hardly "extreme" for a bar of steel. Thing about freedom is, people can claim whatever they wish no matter how silly..... and others can either believe or not believe or interpret it their own way.

Very wise of you to clean out the liquid first. That's a great idea.

 

[people]

I just use a funnel with some plastic tubing. Kind of awkward but was stuff I had on hand. I do like the oil pour spout. I also just use dry patches. The nice part is they dry fast and if not too dirty can be reused.

 

[LHSmith]

For those interested in the PS article I mentioned above, It is in the Feb. 2005 issue written by Fred Barker, a retired metallurgist. I will quote the summary: "So the following recommendations may be made to reduce heat checking in a bore, and thus extend barrel life: 1) in extended firing (e.g., high-power and long range competition and prairie dog shooting) keep the barrel warm; keep the number of cool-to-hot-to-cool cycles as low as possible; rack the rifle in the sun between relays; 2) if the outer surface of the barrel becomes too hot to touch, cool it down to where it can be handled-this to reduce the nitridation reaction on firing; 3) do not run any coolant down a hot bore: that would give thermal shock and induce cracking; 4) preheat the bore before firing........... 5) use a rifle configuration that maximizes heat flow from the barrel to the surrounding air: enlarge the barrel channel......use a bedding block set-up that exposes most of the barrel...."
The science behind this: 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. There also is a complication that the surface of the bore's throat is thinly nitrided by the nitrogen in the powder gas, giving a brittle coating that behaves differently than the underlying steel. The depth of the nitriding is a function of total number of rounds fired, duration of burn of the powder gas, temperature of the throat surface just prior to firing, the content of nitrogen in the powder gas( higher in double base powders?).... The most important factor in heat checking, though, remains the temperature difference between the very thin skin of hot steel and iron nitride at the surface and the underlying steel substrate- i.e. the large temperature gradient....this gradient causes the surface to expand ( on firing) or contract (on cooling) relative to the substrate and to give the thermal stresses that lead to cracking."

 

[DogBuster]

I usually take two table guns....one 'up front truck gun'.......

Sham Wow works great from the ice water cooler..over the throat

Or the 'Crown Royal' bag...the Sham Wow stays wet longer...

or keep your solvents on ice too........ ;D

 

[dennisinaz]

I have a range that I can use to shoot 100 yds close to the house when I want. There is an ice machine and filtered water spigot. I fill my cooler with ice and water and set it on the bench next to the one I use. IF I am shooting a rifle with a synthetic stock, I just hold the barrel under the nozzle of the cooler and flood the OUTSIDE with ice water. Takes about 10 seconds to completely cool a barrel that is very warm. I then let it sit for 60 seconds to normalize.

I blow the water out of the gap between the barrel and stock with just puffs of air. As long as I point the barrel down, no water gets into the important stuff.

I also have CO2 that I can blow down the barrel for the walnut stocked rifles. It's typically over 100° every range session this time of year.

Compressed air cans are nice but spendy!

 

[Rustystud]

A puff of Nitrogen down the barrel, cools and displaces moisture. Tank and regulator not to expensive.
Nat Lambeth

 

[Gabe22BR]

Portable oxygen tank and hose will work fairly quick

 

[jlow]

Sometimes the old tried and true is still the best I quote the following about the Vickers HMG using water cooling:

"The weapon had a reputation for great solidity and reliability. Ian V. Hogg, in Weapons & War Machines, describes an action that took place in August 1916, during which the British 100th Company of the Machine Gun Corps fired their ten Vickers guns continuously for twelve hours. Using 100 barrels, they fired a million rounds without a failure. "It was this absolute foolproof reliability which endeared the Vickers to every British soldier who ever fired one."

Thats firing 10,000 per barrel continuousely...

 

[LHSmith]

Portable oxygen tank and hose will work fairly quick

NO this is a disaster waiting to happen....O2 and any trace of oil

 

[jlow]

Portable oxygen tank and hose will work fairly quick

NO this is a disaster waiting to happen....O2 and any trace of oil

Cannot think of a worse mix to put in a barrel....

 

[jlow]

Sometimes the old tried and true is still the best I quote the following about the Vickers HMG using water cooling:

"The weapon had a reputation for great solidity and reliability. Ian V. Hogg, in Weapons & War Machines, describes an action that took place in August 1916, during which the British 100th Company of the Machine Gun Corps fired their ten Vickers guns continuously for twelve hours. Using 100 barrels, they fired a million rounds without a failure. "It was this absolute foolproof reliability which endeared the Vickers to every British soldier who ever fired one."

Thats firing 10,000 per barrel continuousely...

The reason this works so well is because as long as the cooling jacket is not under pressure, the water keeps the temperature of the outer skin of the barrel to 100 degree C, no wild swings in temperature and the cooling is continuous while you shoot. I don't imagine that building a jacketed rifle would be really that hard. The jacket would not have to be too big but there of course will be a significant weight penalty.

 

[amlevin]

Some years ago, there was an article in Precision Shooting magazine in which the author pointed out the difference in surface area of different barrel finishes and shapes. His point was that if you want to maximize surface area that a coarse sandblasted finish has more area than fluted, and that a polished finish was the worst in this regard. I guess that if you were really trying to do all that you could, you could do both.

There is also the issue of shade. Direct sunlight on a barrel will warm it up quite a bit over what it would be in the shade, especially on a hot bright day.

Back in my college days, I made money by overhauling (ring and valve jobs) gas engines for a delivery service, 600 series Fords and the like. I did this work in an unshaded parking lot, and in the heat of the summer had to cover my tools so that they would not become too hot to handle. They had polished chrome finishes.

Absolutely Boyd. There is a reason why the space shuttle nose and leading edges on the wings are black, rather than the white color on the remaining parts of the body of the aircraft!

Edit: The black color sucks up heat at a faster rate, but also gives up that heat at a MUCH faster rate! The remainder of my rifle barrels will be finished with a cerakote finish, rather than a pretty polished finish.

Only problem with "Black" on a rifle is that all the "snooty" BR Shooters then give you crap about owning a "Black Rifle". Same guys who not only leave their barrels in the white, but they often polish them until they shine like a "Pimp's Cadillac".

 

[people]

The reason this works so well is because as long as the cooling jacket is not under pressure, the water keeps the temperature of the outer skin of the barrel to 100 degree C, no wild swings in temperature and the cooling is continuous while you shoot. I don't imagine that building a jacketed rifle would be really that hard. The jacket would not have to be too big but there of course will be a significant weight penalty.

There was a story in the varmint hunters mag way back from the 90's late 90's. This guy made a water jacket for a bolt rifle. It was connected via tubing and a pump. If I am remembering correctly the article stated the pressure needed to be consistent for maximum accuracy.

I am sure someone with time and good Google fu can find that article.

 

[amlevin]

For all those that want a fancy "cooling system", here's the ticket.

An Igloo cooler
A coil of copper pipe
A piece of sheet metal
A large Computer fan that will run on 6v or 12v
A piece of surgical tubing
A bore guide with o-rings

Drill a hole in the sheet metal and about 2-3 inches from one end of the interior of the cooler.
Drill a hole in the one end of the cooler.
Install coil of copper with one end inserted in the cooler hole and the other in the sheet metal bulkhead. Seal the pipe and around the edges of the bulkhead with some silicon sealer.

Cut a hole in the bulkhead end of the cooler that will allow the fan to be mounted in it.

Attach surgical tubing to the end of the copper coil where it exits the cooler and the other end to the bore guide.

Remove bolt, insert bore guide. Fill the coil area of the cooler with ice and connect the fan to your battery.

Nice cool air is now pushed through the bore and will cool even the hottest barrel in short order. No nitrogen, CO2, NOX, etc to purchase. Just a bag of ice, many of which make overnight in their own refrigerators.

For those who might be worried about condensate from the tubing, just put a "T" at the outlet with a "drain stub" on it pointing down.

Don't waste money on the cooler by buying new, just hit Goodwill or your neighborhood Garage Sales. For the computer fan, check out your local Electronic's recycler.

 

[Gabe22BR]

NO this is a disaster waiting to happen....O2 and any trace of oil

Where did the oil come into equation?

 

[fguffey]

Where did the oil come into equation?

I have bottles and gages for welding, it is stamped on the gage "Do not oil", it is said oil will burst in flames in the presence of Oxygen.

F. Guffey

 

[LHSmith]

NO this is a disaster waiting to happen....O2 and any trace of oil

Where did the oil come into equation?

Bolt lube, gun oil, oil impregnated gunstock

 

[vmaxpro]

Shooting in the phoenix summer the damn barrel is hot before you even start shooting. I sometimes will use a cold air gun from my machine shop for quicker cool downs. I dont feel like being at the range for hours when its almost 120 out haha

 

[snakepit]

I live in Houston. It is smokin' hot down here all summer. We used to take a mattress air pump and pump ambient air thru the barrel. It WILL cool your barrel down quickly during the Spring, Fall and Winter. However, it never worked during the summer. It cooled it down faster, however, "faster" is still slow.

Ben, I use a method similar to what you do. I use a D Cell Mattress Air Pump. I take an empty shell of the caliber of barrel I am cooling and cut the primer end off and insert a vinyl tube with some silicon glue on it into the shell. The other end pushes on to a variable tubing size adapter that came with the pump. Take the hose and guide the shell into the chamber and turn the pump on. During those hot summers I put the pump into a plastic container which I set in a styrofoam container with blue ice packs or ice. I put several holes in the lid, one for the air hose and a few others for the air to get into the styrofoam container. I also use the temperature strips on the barrel.

 

[people]

NO this is a disaster waiting to happen....O2 and any trace of oil

Where did the oil come into equation?

Bolt lube, gun oil, oil impregnated gunstock

Come on just oil the inside of the tube and let it rip. A nice mini flame thrower.

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