When I go to the range I spend most of my time letting my barrel cool off. I have a .30-06 with a standerd Ruger
stainless barrel. For load developement I don't mind the wait, but for plinking and target practise what is a practical
limit for barrel temperature. What does "Hot to the touch" mean? I'm not overly fond of the orignial barrel, so I don't
need it to last 10,000 rounds, but I don't want to ruin it every trip to the range either.

How hot is too hot for a decent life span? What pace of firing is too fast for a sporter rifle?

Lay your hand on the barrel ahead of the scope....can you keep it there for 5 seconds? If not, slow down.

During the summer months I always take little cooler with some ice and a couple cans of soda to the range.

Was working this summer with a new M700 stainless .300 Win. Mag. (700 & stainless, well, I just lost Jack's attention and respect ) Finally managed to get 7/8" 7 shot groups straight out of the box - it's hard to hate a rifle like that. But back to the subject.

Dang thing gets hot after 2-3 shots and took forever to cool in 90+ degree weather. So I just turned it upside down and rubbed an ice cube over the barrel from chamber to muzzle. It melted the ice cube in short order but cooled that barrel down in about 30 seconds. Being upside down the water just ran off the end of the muzzle. And by "cool", I mean definitely cool to the touch. Repeating this procedure after each 3 shot group let me shoot a bunch more loads in a much shorter time.

Now a question for Jack (if he's still reading )or anybody else. Given that the barrel is not really cooking, just "too warm to the touch", does this offer any possibility for long term adverse effect to the barrel? I thought about slight warpage but group impact points stayed the same (allowing for increasing powder charge), and no water gets in the muzzle - Important Point! Obviously if water gets between the barrel and stock it can present problems for rust or perhaps stock warpage but with the rifle upside down and muzzle down this does not happen.

I remember reading that Rick Jamison uses a bucket of water and a small hose setup to run water down his barrels to cool them quickly so water cooling seems to be an acceptable practice, plus ice cubes are more convenient than a suspended water bucket.

Anybody else tried this? I have taken to using it on my chrome moly rifles as well, again taking precautions to keep water from between the barrel and stock.

JBelk has given you some good advice.

To put values to that finger feeling - at 55C you would put something down quickly, at 60C you tend to put things very quickly at 65C you just drop it!

Years back I worked in a laboratory and we had to titrate something at 60C. Initially you used a dishcloth to hold the flask - but after a month or so you could hold the flask with your bare fingers. We could never manage to handle 65C.

Using that bit of knowledge,I know that 5 to 8 shots through my 8x68 brings the barrel temp to 60C+.

cheers edi

Jim, I don't know if it "hurts" anything or not, but I do the same thing in the winter. Just grab a hand full of snow, slide it up and down the barrel, and, presto-chango, a cold barrel.

I DO usually let the barrel sit a while longer to let things "even out".

I've read about all sorts of barrel coolers, water, compressed gas, all sorts. I see some benchresters just use a wet rag draped over the barrel. FWIW, Dutch.

Easy method to speed barrel cooling..take out the bolt and let it stand on it's butt..the barrel will act like a chimney and speed cooling.

Standing a rifle with the barrel vertical and the action open is pretty standard and certainly aids in cooling but it still takes a good long while to get the barrel back to even ambient temperature in the hot summer months. I used to use a wet rag to rub over the barrel but even that took time.

The ice cube method will cool that barrel down below ambient temperature within 30 seconds. My only worry was whether or not such a rapid cooling could harm a barrel and I am careful to spread it as evenly as possible over the entire surface. I figure that since an ice cube is right about 0 degrees C it is probably less drastic than exposing the barrel to -5 C or even colder air in the winter after heating it up with 3 or 4 shots.

I've used the ice cube method for 30 odd years without damage or adverse reactions UNLESS you have a barrel that's still got stresses in it.....that one walked the "group" across the page like rat tracks anyhow.

It's good to shoot, wipe with ice and then let the temperatures even out by letting it sit another 30 seconds or so.

If you get really serious hook up a CO2 fire extingisher to a hand nozzle with a long tube on the end so you can squirt CO2 into the chamber and down the barrel. A five second squirt will cool any barrel down to room temp.....sometimes 8 seconds causes frost. DON'T shoot a frosty barrel!!!

CO2 is the preferred way to cool beer in an emergency too.

In high power shooting I shoot 20 rounds "rapid " and 20 rounds slow fire at the 300 yard line in 15 min. barrel life is 800 to 1500 rounds for a 30 cal cm barrel. you also have to throw in the other 48 rounds in a match sighter and slow fire 200 and 600. you do not want to get near the barrel after a rapid string. How much range fireing will your barrel stand shooting and cooling. A September High Power match if Florida is a exercise in endurance.

I cheat, I've got an air conditioned building that I load in and shoot out of. I set the rifle in front of a powerful fan and by the time I have another load ready to try the barrel is cool.

I usally only get about 5 rounds out my my sporter rem 700 .22-250 before its getting a little warm for my liking. I simply do as others have said and open the bolt stand it upright and let it act as a chimney.

I then pick up another gun and have a few shots with that then once thats hot i go out and check my targets (i dont shoot on a range usally in a farmers paddock (farmers feild i supose in the US)meaning when i want to check targets i simply go and check them.

For myself i think its more important to take an hour more and not rist hurting my barrel then to be in a hurry and cause some damage.

Why not try some dry ice? It ain't near as messy as "wet" ice.

FWIW

This is based more on things I learned about metallurgy when I did alot of varied "expert" welding, than on guns, so take it for what its worth...

Rapid cooling of most metals is, in general, a "bad thing"...By that I mean a rapid change in temperature of a couple hundred degrees or more... So, I would say if barrel is not "too hot" (no more than a few (5-10 shots?) the ice cube trick probably OK...I would hesitate if barrel was hotter, cooling "device" much colder(dry ice).. Rapid cooling can lead to "brittleness" and cracking (even if microscopic) which I really would prefer not to have in an action or gun barrel... I'm playing with a lightweight barrel, which has been radially "fluted" with very small grooves...This gives roughly 3 times the cooling area (as smooth barrel), much more than the typical longitudinal fluting seen on heavy barrels... I'll post results when I get gun togther

You're barrel is too hot when molten chunks of barrel steel are being blown out the muzzle!

dfaugh---

Quench embrittlement occurs when steel is quenched from above the temperature of transformation. This is usually about 1300 degrees. Bright red. This point is easy to determine. Heat the steel until it suddenly becomes non-magnetic. Most barrels don't have enough carbon in them to become brittle anyway. Try it with a torch.

GSF-1200

Stock finish bubbling out of the barrel channel along with thick smoke is another way to determine when it's too hot.

Several years ago my shooting partner toasted a 220 Swift M-77 in a groundsquirrel town. We decided to finish it off and go back to the shop and put on another barrel......so we experimented.

About the same time the stock finish started frying and smoking the bullets stopped making it downrange. There were puffs of gray steam about 30 yards down range where the bullets came apart. Mirage through the scope became so bad it was impossible to sight on varmints and the smell of burning varnish made us sit the rifle outside the truck to cool off.

The total rounds to do this was less than 50.

Hey Guys, I just had both knees replaced. The hospital sent me home with 2 coolers designed to keep my knees iced down. it looks like a six pack size cooler and comes with a pump and a bladder that they wrapped around my knees. The little pump kept the ice water circulating around my knees. The hose looks to be about 6ft long to the bladder. Why couldn't a guy wrap the bladder around the BBL. in front of the scope and circulate ice water around the BBL. and not even get it wet, kinda like a cool can from the old hot rod days?

Jbelk,

Did you try an accuracy test on the Swift after the barrel cooled off? Or check for throat damage? Just curious�

Thanks,
Ben

Ben---

After the barrel cooled I shot it off the bench. Groups were in the two inch range.

I sectioned the barrel and used it for a class in California...somehow it got away from me.

The first two inches of throat looked like a charcoal briquette.

Jbelk,

Wow! Looks like I�ll have to avoid rapid fire in my guns until I make more money! Otherwise I wouldn�t be able to replace my barrel.

My guess is something that evaporates easily would cool a barrel quickly. Say 70% isopropanol. Get it at the drug store and then put it in a spray bottle. Then you could spray it on the barrel and in short order the liquid would evaporate and your barrel would be cool. Just don�t smoke while doing this! Or breathe to deeply. Ether would be about perfect�

Ben

I need to clarify something before I get any more "You're full of shit" emails... The Swift was pretty tired with about 800 hot loads through it BEFORE the rapid fire exercise. My partner didn't burn up a brand new barrel in less than 50 rounds.

On a similar note--- the last time S. Idaho had a jackrabbit infestation I had a Ruger #1A K-Hornet too hot to touch......and it was ten degrees (F) above zero!!

Ben Wazu---

CO2 is more effective than rapidly evaporating solvents and has no hazard asscociated with it. Go by any fire extinquisher shop or to the welding store to buy it. By sure to insulate the hose. It can frost-bite you in seconds.

My concern for getting a barrel too hot has always been about increased throat erosion. The temperature on the surface of the throat is going to be much higher than what migrates to the outside of the barrel, and I think methods that cool the inside of the bore are better, as you can get a false sense of security with a cool outer barrel while the throat is still really cooking. Now I'm saying that from the seat of my pants, so next time I have a centerfire out that I'm doing some shooting with I'll take a thermocouple and do some measurements.

I usually shoot with a few guns so I just open the bolt and stand them upright, but I have seriously toyed with the idea of epoxying a small 12v computer power supply cooling fan to a funnel that could set over the muzzle and speed up the draft.

Mark,
You are correct in your concern about throat erosion and too hot a barrel. That's the first thing that happens.
I don't know who posted it but the idea that you shoot out a barrel in HP in 800-1200 rounds is BS. Unless you are shooting some odd high pressure caliber... I've heard people can do that using something like a 300 Ultra-mag. But not a .308 or 5.56...
I used to get about 3,600 rounds out of a good Kreiger or Obermeyer barrel before I noticed a long range degradation in accuracy (Usually, the gun would continue to group fine at 200 and 300) But at 600 things would get iffy. By 4,000 rounds the throat was usually gone in terms of match accuracy (which I assure you is quite adeqaute if you can keep 10 shots in 1 MOA.
Since I started using moly my throat life has extended to around 5,400 rounds. And that includes lots of 20 shot rapid fire strings in 90 degree weather. Mind you these guns have a heavy barrel which helps "absorb" all that heat. But it also makes cooling off a slower proposition as well.

Interesting ideas outlined here. Fans, CO2 etc. etc. "Firearms enthusiasts" are definitely a gadget oriented crowd.

Since I am not dealing with molten steel or frying stock finishes, but just the "too warm to the touch" barrel of a .300 Win. Mag. Sporter after three shots, seems like the ol' handy dandy, cheap to make, easy to transport, standard issue M-1 ice cube will still suffice for my needs.

Interesting topic and perhaps quite a concern for shooters seeking to maintian the best possible benchrest accuracy. I'll conceed there are members here with more technical expertise than I will ever have. But that said, my own personal observations over 45 years of shooting doesn't really support most of these posts at all.

My first rifle many years ago was an old enfield 30/06 and I got it so hot several times that the stock was smoking. Once I got it steaming hot and carelessly pitched the rifle up to a "shoulder arms" position so I could navigate down a ravine with it and some other junk I was trying to carry in my hands. In the process the rifle rolled over enough to place the hot barrel against my bare neck. I thought I was branded for life! Fortunately I healed.

And I've got Ruger Mini 14's so hot a few times it's a wonder the stocks didn't ignite.

My point being, I never noticed any accuracy difference after these incidents. My old 30/06 would shoot just under 1" when I got it and as best I could tell when I finally traded the old devil off I had shot something like 7 - 8,000 rounds thru the bore. In the end, the rifle would still shoot 2 1/2" groups at 100. The Ruger Mini 14 was never much better or worse than a 2 1/2 inch rifle on target.

I think it would take some serious and deliberate attempts to burn up barrels if the theories put forth here were valid. And by the theories put forth here it would be almost impossible to keep machineguns in working order.

Gentlemen, with all respect, I think the case is a bit over-stated. JMHO

Pecos,
IN many ways you are correct. However, I will reiterate my point about loss of long range match accuracy after 4000 rounds or so of .308 (before I moly coated my bullets...5,400 after coating) I'm speaking here, strictly in terms of long range match accuracy. When a a barrel gets worn the first place you will notice it is the long range performance of the bullets. At 200 and 300 yards the difference is normally not perceptable. But trust me, you know when your barrel is getting worn as your 600 yard scores start to go down and holding the gun in the 10 ring seems to depend more on the position of the moon and the stars than your ability to call your shot. This isn't just my experience but literally quite common among HP shooters with tons of experience. Trust me...I wouldn't spend $500 rebarreling my M1A if I didn't need to. Its on its fourth barrel...btw!
Bullet dispersion is only rarely linear in my experience and a 1/2 MOA rifle at 100 yards ain't necessarily a 1/2 MOA rifle at 600 and visa versa.
In older rifles throat erosion is almost universally the culprit.
I've shot out maybe a half dozen MG barrels during my Army career. First, they are chrome lined. Second, nobody takes a MG barrel and shoots groups with it. Third, we expected the thing to "pattern" and produce a spray of bullets known as a beaten zone designed to supress a point target or perhaps engage a massed target like several soldiers. As stated, all MG barrels are chrome lined and resist throat erosion better than an unlined bore. Finally, MG barrels wear at a pretty fast rate...probably more than your realize! In 18 months of leading a tank platoon of M1 Abrams tanks (4 tanks) each with 2 7.62 MGs and one .50 Cal MG I'd easily estimate that we replaced half of the .30 barrels and maybe 1 or 2 of the M2 barrels. Mechanical pounding of the MG barrels by the action of the weapon also took its toll, however... As a Cavalry Troop Commander I can't even begin to tell you how many barrels I replaced on my tanks and Bradleys but it was a bunch...
I've heard many people claim upwards of 10,000 rounds through a sporting rifle. I'm sure its possible....ever shoot it beyond 300 yards?