Barrel Cooling

[joeb33050]

There's thought that hot barrels make big(ger) groups. Pat I on the CBA site has posted a description of his fan-blowing-air-through-the-barrel design, with pictures. Jeff and Pat and others believe that cool barrels shoot better. I'm a water cooler.
I've spent a lot of time thinking about this and browsing at the hardware store. There are brass and copper and aluminum things that one could put in or on the barrel to cool it down. No elegant solution has come to me yet.

I keep going back to the water cooling. It's easy, clean, cheap, doesn't require a lot of equipment (perhaps a problem there), and fast-pour 12 ounces of water through the barrel and it's cool.

The possible drawbacks are that the water may injure the barrel, the water may get into the action and rust everything up and it doesn't require a lot of equipment.

I seem able to pour the water through the barrel without getting any in the action. A 3/8" O.D. plastic tube jams right into the chamber neck. A 3/8" I.D. 2" long plastic tube goes over the first tube, and a funnel jams into the other end.

I put the gun forward, resting on the front bag at ~ the front of the trigger guard, barrel aimed down sharply. Jam in the tubing apparatus, pour the water from a plastic water bottle through the barrel, the water drains out onto the ground in front of the bench. Remove the plastic apparatus, push a patch through the barrel, clean if desired and done.

Will the water hurt the barrel steel?

I went to Home Depot, they've got oderless mineral spirits that I clean with, acetone, turpentine, alcohol, MEK--alternatives to the water but requiring collection at the muzzle for re-use.

If water in the action rusting the dickens out of everything is viewed as a problem, the alcohol would solve it.

Why not water?

joe b.

[Trapshooter]

Water's got to be the best! Besides all its other positive attributes you mentioned, it has the highest specific heat. It removes more BTUs per ounce from the metal than any of the alternates you mentioned.

In addition to lower heat transfer, some of the solvents you mentioned limit the types of plastic used for transport and the tubing.

The only way I could see water possibly causing injury other than rust would be if there were a high concentration of other stuff in it. Perhaps if one cooled the barrel with very hard mineral water, and dried the barrel poorly with a patch on a regular basis, it would be possible to end up with something like boiler scale in a miniature form.

Trapshooter

[MT Gianni]

What temperature do you keep the water at? In a cooler of ice at 35F or in the Florida shade at 95F? Florida sun at?.Are you monitoring barrel temperatures with a finger or a thermometer and what do you consider to be hot. Do your groups shrink consistently and measureably after the water treatment? I am just curious as when my gun gets too hot I open the action and shoot another gun. I don't currently shoot timed matches. Gianni

[BruceB]

My system is also water-based.

A large insulated jug (2 gallons?) full of ice and water is placed on the van's roof, with a plastic tube leading down to the benchrest. A valve on the bottom end of the line controls the flow, and a six-inch-long tube attached to the valve gets the water to the front of the chamber. As Joe does, the barrel is positioned somewhat muzzle-down and the water flows out onto the ground. About fifteen seconds of ice-water flow, and the barrel is very cool.

Because I don't want to disturb the "bore-conditioning" established by firing a number of cast rounds, I blow the barrel dry with compressed air from a 15-gallon tank under the benchrest. Such tanks are available at auto-supply stores for $30 or so. 15-20 seconds of airflow usually does the trick, and shooting can continue. Using compressed air avoids introducing anything that might destroy the conditioning established in the barrel. That's my thinking, anyway. Water and air seem to have no effect.

MT Gianni raises a good point about temps. I have a digital thermometer with a six-inch probe, and when my fingers tell me that a barrel is "HOT", it's usually around 180 degrees Fahrenheit at 6" inside the muzzle. This is logical, since most of us can't tolerate the boiling-point temp of 212 degrees. As steel goes, 180 degrees isn't really very hot, and I don't concern myself with "thermal shock" or other such minutiae.

[dbldblu]

I was just today out shooting an old SMLE that vertically strings as the barrel gets hot. Today I tried firing just 3 shots and then rubbing the barrel with an ice cube. The ice cube melts fast. I held the rifle upside down so that the melting ice-water did not get under the stock. Most of the barrel is exposed on this rifle, there is no forend top wood. Then I set the rifle aside to even out temperature wise while I checked the target. This worked great; I had no stringing. Later, when I cleaned it, I went over the barrel with an oily cloth and I don't expect any problems with this.

[trk]

So, aside from the water cooling question, is there evidence of size of group correlated to temperature of a barrel? Could it be that cold is large, warm is small and hot is small again (or just the reverse or some other function)?

Cooling is not a bad idea, as it has the potential of keeping fingers from being burned or at least kept within a narrower range of temperatures than simply from cold to hot.

[joeb33050]

What temperature do you keep the water at? In a cooler of ice at 35F or in the Florida shade at 95F? Florida sun at?.Are you monitoring barrel temperatures with a finger or a thermometer and what do you consider to be hot. Do your groups shrink consistently and measureably after the water treatment? I am just curious as when my gun gets too hot I open the action and shoot another gun. I don't currently shoot timed matches. Gianni

I use range temperature water, that's about 92 degrees now. No thermometers are used. A hot gun barrel is hottest over the chamber, cooler but still hot at the muzzle. Over the chamber, with slow powders, it is almost too hot to leave my finger there after 2-3 foulers and 10 record. There's no doubt in my mind, it's hot. I think the gun shoots better after cooling. See below.
joe brennan

[joeb33050]

So, aside from the water cooling question, is there evidence of size of group correlated to temperature of a barrel? Could it be that cold is large, warm is small and hot is small again (or just the reverse or some other function)?


The/some CBA folk think that cool barrels shoot better than hot. On the site there are references to several of the better shooters at last weekend's Nationals using cooling fans etc. I think I see groups get pretty big as the barrel gets very hot, but a test protocol would be pretty involved.
joe brennan

[piwo]

So, aside from the water cooling question, is there evidence of size of group correlated to temperature of a barrel? Could it be that cold is large, warm is small and hot is small again (or just the reverse or some other function)?


Hmm... I read an account, (I think in "The Accurate Varmit RIfles") of a guy who shot a group in the 0's by shooting one shot from his rifle at a target on five successive cold morning. No cleaning, no "windage" or test shots, just 1 shot for record over a 5 day period from a cold barrel. I believe super hot barrels are not as accurate, but only because with my limited skills I have experienced groups opening up and stringing shots. BUT, was this the result of improperly bedded actions, scopes, inability to shoot through the soup (mirage) and so forth....

[arkypete]

When ever this topic comes up I'm reminded of a cartoon I once saw. I think it has it's origins during WWII. It's two Marines arguing about whose turn it was to stand up and whiz on the machine barrel to cool it during a fire fight.
Jim

[leftiye]

It's probly not just the hot barrels. There's probly no such thang as perfect bedding, nor many barrels that are completely stress relieved. It's the delta T- the barrel changing temperature.

[Bret4207]

If I read my Accurate Rifle correctly, the ads at least, isn't cryogenic treatment supposed to cure all this? Hmmmm, could it be truth disputes advertising?

This is far beyond the type of shooting I do. I can't recall ever shooting a rifle so fast I heated the barrel to the uncomfortable point. Maybe if I shot High Power rapid fire would be an issue. Who does this affect?

[Charley]

I don't shoot fast enough to need a water system, but I do use a cooler made from a battery powered air pump. If you really needed to drop the temperature, it would be easy enough to run a copper coil in an icebox, and connect the air line to run thru the icebox. I've seen homemade coolers for tent camping made the same way, shouldn't be hard to whip something up.

[Cimarron Red]

I do a lot of BPCR silhouette shooting. And shooters in this game typically use one of two methods for controlling the black powder fouling -- a blow tube or wiping between shots. Those who wipe (and I'm in this camp) use various concoctions for wiping fluid. Most of the guys I shoot with use water and water soluble oil such as the oil used as a coolant/lubricant in machining operations. Some shooters take it a step farther and use distilled water. My dilution is 10 parts water to 1 part oil. The oil residue acts as a rust preventive as well. This solution could be used as a barrel cooling medium with the added advantage that any of the mixture that might find its way into the the guns action will not cause rusting.

[Pat I.]

Just my opinion on the subject but barrel heat is going to affect everyone who shoots cast bullets, although those shooting during a timed event more than others.

What I think the problem is with hot barrels and cast bullets is that the lube's properties start to change as the barrel gets hot. I've had lubes that worked great at 80 degrees act up at 40 so it's possible the same thing is happening if the temperature in the barrel is 140. A simple test to see if heat is having an affect on your groups would be to fire two foulers followed by a ten shot group shot as fast as you can after getting a good site picture and compare it to the same 12 shots with a minute or so cool down period between shots.

[Junior1942]

About a year ago I thought I'd get rich by making and marketing a barrel air-cooling device using batteries and a 5VDC computer fan and vehicle batteries and a 12VDC computer fan, which I installed inside PVC sewer pipe. Into the sewer pipe, I used PVC water pipe which slipped over the muzzle. I sealed the water pipe/barrel junction with something, maybe foam. So I made one of each and bought an infrared thermometer and did extensive testing.

The rifle used was a Win 94 20" octagon 30-30. The spot measured on the barrel was the hottest spot, which, IIRC, was a couple of inches forward of the chamber. I'd fire rounds in one minute intervals until the spot reached a target temperature, say 150 degrees since I can't remember the actual target temperature.

Target temp reached, I'd stop firing and measure the spot in one minute intervals and record the measurements. When the barrel cooled to air temp, I'd start firing again and repeat the process using the fan for cooling this time.

As expected, the barrel cooled MUCH faster with air forced through it. Actually, it was much easier to make a device to suck air through a barrel than to make a device to blow air through a barrel. Then I wondered how fast the barrel would cool if I simply leaned the rifle against the bench with the action open and the barrel pointing straight up.

Guess what? The chimney effect cooled the barrel almost exactly as fast as did forced air.

As my bench was on my front porch I ran a hose into my air conditioned living room and forced cooled air through the barrel. That cooled the barrel much faster. However, here in Louisiana the high humidity caused much condensation in the rifle barrel when the cooled air hit it. Water actually dripped from the chamber.

In short, unless you live in a very low humidity area, forget forced air barrel cooling and simply open your rifle's action, point it straight up, and let the chimney effect go to work.

[Pat I.]

Here's what I use.

[jhalcott]

I shot a 5 shot group with a .223 remington 700 in 95 degree weather a week ago. The group went about 1 1/2". Today in 65 degree weather The group was sub 1". Every thing else was the same. The ammo was from the same batch loaded 3 weeks ago. IF I did not use the chimney effect,I would turn my gun over ,with the action up and muzzle down, before I'd use water to cool the barrel.
The groups were fired one shot a minute,timed. I USUALLY take more than 1 gun to allow cooling of the barrel.

[Arnie]

Why not use a CO2 fire extinguisher or a CO2 tank from Paint ball guns and let the CO2 go through the barel slow enough to pick up the heat .Arnie

[Junior1942]

Guys, if you'll think about it, the chimney effect works on both the inside and the outside of the barrel. Forced air through the chamber or the muzzle works only on the inside of the barrel.

[joeb33050]

Why not use a CO2 fire extinguisher or a CO2 tank from Paint ball guns and let the CO2 go through the barel slow enough to pick up the heat .Arnie

Becausre the CO2 costs money and requires equipment and it kind of scares me, putting real COLD in the rifle barrel.
I like the chimney effect but we can't stand guns up at the range-must be on the bench between relays.
joe brennan

[Char-Gar]

I use an air cooling system. I pull the bolt and day dream a while until it cools. I day dream mostly about Raquel Welch in her salad days.

[Pat I.]

I know there's not a lot of competitive shooters here but like Joe said you might not be allowed to stand the gun up between relays and you wouldn't want to disturb the bag set up anyway. As in most things relating to cast bullets and guns in general there's always going to be more than one way to skin a cat and if something works for you and you're happy with the results go forth and prosper. My little pump and hose works for me.

[buck1]

Great tip!! Thanks buddy!![smilie=w:






About a year ago I thought I'd get rich by making and marketing a barrel air-cooling device using batteries and a 5VDC computer fan and vehicle batteries and a 12VDC computer fan, which I installed inside PVC sewer pipe. Into the sewer pipe, I used PVC water pipe which slipped over the muzzle. I sealed the water pipe/barrel junction with something, maybe foam. So I made one of each and bought an infrared thermometer and did extensive testing.

The rifle used was a Win 94 20" octagon 30-30. The spot measured on the barrel was the hottest spot, which, IIRC, was a couple of inches forward of the chamber. I'd fire rounds in one minute intervals until the spot reached a target temperature, say 150 degrees since I can't remember the actual target temperature.

Target temp reached, I'd stop firing and measure the spot in one minute intervals and record the measurements. When the barrel cooled to air temp, I'd start firing again and repeat the process using the fan for cooling this time.

As expected, the barrel cooled MUCH faster with air forced through it. Actually, it was much easier to make a device to suck air through a barrel than to make a device to blow air through a barrel. Then I wondered how fast the barrel would cool if I simply leaned the rifle against the bench with the action open and the barrel pointing straight up.

Guess what? The chimney effect cooled the barrel almost exactly as fast as did forced air.

As my bench was on my front porch I ran a hose into my air conditioned living room and forced cooled air through the barrel. That cooled the barrel much faster. However, here in Louisiana the high humidity caused much condensation in the rifle barrel when the cooled air hit it. Water actually dripped from the chamber.

In short, unless you live in a very low humidity area, forget forced air barrel cooling and simply open your rifle's action, point it straight up, and let the chimney effect go to work.

[1Shirt]

Junior, Ben Franklin was supposed to have said "common sense is not a common virtue!" The chimney effect is common sense! As a p-dog shooter, I try not to shoot over 20 rounds befor I switch rifles for bbl. cooling. Just one rifle would slow up my shooting.
1Shirt!:coffee:

[redneckdan]

several years back (like in the 90s) I remember reading in a gun rag about a pair of varmint rifles that we built with water jackets and fed from a submersible 12v pump marine cooler stocked with ice and water. They said they were able to shoot as fest as the P-dog appeared and never over heated. I haven't seen that issue around in a few years, I beleive the article was titled "fire and ice".

[Skrenos]

several years back (like in the 90s) I remember reading in a gun rag about a pair of varmint rifles that we built with water jackets and fed from a submersible 12v pump marine cooler stocked with ice and water. They said they were able to shoot as fest as the P-dog appeared and never over heated. I haven't seen that issue around in a few years, I beleive the article was titled "fire and ice".

I have that magazine with that exact article. If I can find it, I'll scan it.

[crowbuster]

When shooting P- dogs i use the cryo cuff I got when i had my shoulder surgery, put Velcro on the sides and run it longways on the barrel, unit is self contained or can use a power inverter off the truck to power circulate the water instead of manually lifting the jug, works for me.

[Topper]

Has anyone tried plain 91% alcohol?
I know that it will strip the oil from the barrel but it also evaporates quickly.
I've seen a couple of shooters using a rag dampened with it to wipe down barrel between shots.

[jhalcott]

Some of the muzzle loaders at my club would use alcohol dampened rags between shots during competition. But said it wasn't necessary when hunting. I guess they had OTHER uses for alcohol then!

[John F.]

One thing that hasn't been mentioned is the damage to barrel steel from increased erosion when shooting through a hot barrel. Cooling the barrel as
frequently as feasible will add to your barrel life. As an NRA Highpower and Long Range shooter, replacing barrels is a regular thing -- and anything you can do to prolong the life of a $500 barrel is well worth it. People shooting mild cast bullet loads should have much less problem with building up barrel heat, but if you are heating your barrel significantly and keep shooting, you're shortening its life.

There's a popular misconception that jacketed bullet friction is what does the damage, and lead bullets are immune. Not so with modern steels -- it's the flame erosion combined with gas pressure that does the damage. A friend works at a bullet manufacturing firm. They have a test barrel in .45 ACP that has been shot countless tens of thousands of rounds and still gives match accuracy at 50 yards, showing no wear. It is ONLY shot with jacketed bullets, but at low velocity (~850 fps) (note: small powder charge, low gas pressure, not much heat buildup) and never gets hot, to speak of. A .243 match barrel, depending on how it's used, can be expected to be toast in 3000 rounds. (Large volume of high pressure gas being funneled through a small diameter tube, and high heat.)

Hope this helps!
John

[brshooter]

Brent, cyrogenic treatment is a joke. I had 4 Hart barrels, 2 froze, and 2 were left alone. All 4 chambered by Miles Hollister (now deceased) at the same time with a proven reamer. Each barrel had appox. 3500 rounds fired thru them during actual matches and all were at the edge of thier accuracy for benchrest, judging by the groups shot with them. An examination of the records kept on each barrel, there was not any differance in accuracy of each barrel.
A metalurist who retired from US Steel, told me the cryogenic treatment works great on some types of steels, tool steel for one, but the chrome-moly and the sulfurized stainless steel used in rifle barrels could not benefit from cryogenics because of their alloy make-up, and it would be a waste of money to do it. I wasted $200+ dollars to find that out.

[felix]

True. All, just about all, tool steels from Japan (name brand) are cyroed. 4140 steels would benefit, but they are about too hard for accuracy barrels anyway. ... felix

[shotstring]

During international shotgun competition, my shooting coach on several occasions stuck the barrels of his Perazzi into a barrel of cold water as the barrels had become too hot to touch with all the rapid fire shooting. If they aren't worried about their $8,000.00 shotguns, I wouldn't worry about water doing damage to a much thicker and more robust rifle barrel. Not too practical to carry a drum of water around with you though, although that would seem to be an ideal solution if one were already present.