Barrel cooling technique?

S

smoker

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New here so I'll say Hello all. My question concerns the proper technique to use between shots. I don't shoot benchrest but do get a gereat deal of satisfaction trying to wring out every bit of accuracy I can. I'm sure this topic has been beaten to death but would really appreciate your patience and information. Thank you in advance, smoker
 
Many newer stocks have cooling vents in the fore-arm. Some shooters drape cold, wet cloths over the barrel. (Personally, I think that would cause the barrel to distort from uneven cooling to one side, but I'm not up to speed on this.)

I'm finding that barrels shoot best when "warmed up." And so the term "cold shots," suggesting less than optimal accuracy.

I shoot, open the action, check the targets, make some notes. Have another look, reload, set up the shot. Slow process where the barrel doesn't heat up much.

Every couple groups I swab the bore, run a patch, walk down-range and check targets while things "cool down." I'm not being "timed" for competition.

But I'm doing what you're doing . . . tactical "snipe shooting" at 300 yds. w/ a .308 Win.

Sometimes in this forum questions get ignored because everyone figures it's "common knowledge." The tech focus on this and most benchrest sites is upper end.

This is a real basic question.
 
Well with 165 viewing my question and not one response I have to consider I'm not asking this question correctly or it's so basic that it doesen't require an answer. smoker
 
Normally, I am able to shoot a five shot group without worrying about barrel cooling, this being with heavy barreled and/or light caliber varmint rifles. My usual standard, for when a barrel requires time to cool is when it approaches a barrel temperature that would be uncomfortable to leave a hand on, on any part of the barrel. There are some who cool their centerfire competition Benchrest rifles with battery powered rigs that circulate liquid through the bore between matches. Others may lay a cold wet towel across the barrel to accomplish the same thing. Most do neither.

If I am testing a thin barreled hunting rifle in a large game caliber, I usually shoot three shot groups, to avoid barrel heating problems, and simply wait for the barrel to cool between groups. From what I see at the range, the average shooter has more to gain by building or buying a set of wind flags and /or improving his rest setup than worrying about minor barrel heat issues.
 
First, I'm no expert compared to these guys.

But . . . .

I agree with the guy who states a barrel is getting too hot when you cannot grasp your hand around it comfortably. Note, it can be plenty warm but you can still grasp it, so this is getting pretty hot.

Another point-- with my 18X scope, I start getting optical distortion up from the barrel when the barrel gets good and hot. It looks wavy, like you are seeing something underwater. I often wonder if this optical distortion shifts the aiming point -- you think your Xhairs are on the aiming point, but the distortion puts you a half inch high?

Once the barrel on my varmint rifle (heavy barrel) gets good and hot, it seems to take quite a while to cool down very much. One good bet is to have a second rifle with you, shoot that one for a while, and just retire the warmed up barrel for about 20 minutes. Even then, it will probably be less hot, but still good and warm.

How many rounds do you normally plan to fire at a range session? I usually try to limit my shooting to 20 or 30 rds. I'm talking here about a practice session, or an ammo testing session.

A heavy barrel has advantages and disadvantages over a sporter-weight barrel. It takes a heavy barrel longer to heat up, but it takes longer -- in turn -- for it to cool down.

I'm surprised there were not more comments.
 
Thank you Boyd Allen. Not being a compeitive shooter I've not had the chance to associate with the folks that know. So I can assume that from a cold barrel I should be able to get at least three shot groups without a cooling period in between. I always wondered how much effect the heating barrel had on group size. Thanks again, and good luck to you. smoker
 
Montana Pete, thanks for chiming in. My question arises from working up new loads. I've been shooting and reloading for more years than I would like to admit to and have always heard about heated barrels causing one thing or another. I'm presently working up a load for my 300WSM....not a pleasure after 10 rounds or so. Old bones. This rifle heats up pretty fast...maybe after 2 or 3 rounds. I suppose it wouldn't hurt to let it cool between every round. smoker
 
barrel heating

Well I used to be way too over concerned with barrel heating. The local guys I was shooting with were telling me 1 to 5 minutes between shoots. As I started shooting more I found this just was not practical. Heating probably has a significant role in accuracy with a light weight barrel. I don't own any of those. I shoot F-class and some BR. In FClass, we shoot +20 shots in 15-20 minutes. My barrel is always so hot I don't want to touch it after a round. In bench rest, I will fire out 5-8 sighters plus five for score or group in the 7-10 minute round. Again warm barrels.

Shoot and enjoy, tiny
 
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I used to pour water down the bore between strings while working up loads. A tight fitting hose in the chamber, poured out onto the ground, a small amount of water will cool the barrel completely, then clean and shoot.
 
That's the stuff I was looking for...actual experience. So with heavy varmint barrels heating should'nt be a problem at all and the sporter type barrels minimal change. Good info, thanks Tiny.

jlmurphy, never tried water but have done the wet towel thing. Major problem with me is that I never know if it's my shooting or the heat. Guess I'm getting an education here. smoker
 
It's hard to beat a wet towel, folded and draped over the barrel its full length. It's simple, inexpensive, no fuss and works as well as or better than anything else. Of course, here I'm talking about stainless steel benchrest barrels and not blued custom chrome moly barrels on pencil thin hunting rifles.

Gene Beggs
 
+ one on Gene's advise, but I sure would not want to get excited or even think about it until the string was finished. If a guy was worried about the time between relays, then I would want to keep the wet towel in a water can full of ice water. Remember, the greater the temperature difference of the wet towel and the barrel temperature the faster you will pull the heat out of the barrel.

Running water out of the spigot at some of these southern range seem hotter than the barrels we try to cool.:D
 
Alcohol

Cooler.jpg
 
Pete ...

Montana Pete said:
Another point-- with my 18X scope, I start getting optical distortion up from the barrel when the barrel gets good and hot. It looks wavy, like you are seeing something underwater. I often wonder if this optical distortion shifts the aiming point -- you think your Xhairs are on the aiming point, but the distortion puts you a half inch high?
Click to expand...

What you're seeing is barrel mirage (heatwaves) which can be introduced after only 3 to 4 rounds down the barrel and ... "will do their utmost to confound your best efforts to read the conditions on the range by introducing another set of mirage into the picture you see through the scope and one that is totally irrelevant to the real condition on the range" ... so says Walley Siebert.

Walley talks about this in his article on Benchrest Optics in the The Benchrest Shooting Primer starting on page 97. (The Primer can be obtained by calling Precision Shooting Magazine at 860-645-8776)

The cure: a mirage shield or shade. Made from something as simple as a piece of paper taped to the barrel and extending from under the scope to the end of the barrel. Sinclair International carries a more sophisticated device for $4.50. It resembles a piece of venetian blind. Go to this site for a view: http://www.sinclairintl.com/prod_detail_list/s. :)
 
Montana Pete said:
..Another point-- with my 18X scope, I start getting optical distortion up from the barrel when the barrel gets good and hot. It looks wavy, like you are seeing something underwater. I often wonder if this optical distortion shifts the aiming point -- you think your Xhairs are on the aiming point, but the distortion puts you a half inch high?
...
Click to expand...

Here are a couple ideas...

IMG_1595.JPG


DSCN2061.JPG


IMG_1525.JPG
 
Cooling

Between rounds, I have started cooling with an air pump that forces air down the barrel. I use a battery-powder minnow bucket pump from Wally World with pipet tips and just push this in my chamber until it losely seats. My logic is that the hot air in the barrel is not effectively transferred out and the cooling is slower. I watched this one day while I was cleaning one gun at the table while another gun I had just finished shooting was starting to cool. I could clearly see the mirage caused by the hot air slowly coming out of the barrel from my angle and the position of the sunlight. I would roughly guess it cuts cooling time in half. This summer I will get temperature that attaches to DMM and due some formal quantitative test of cooling with and without the pump. I can without a doubt say it helps.

Luck, tiny

Pump-3.jpg

pump-2.jpg

Pump-1.jpg
 
I can't remember seeing any thread where I got more useful ideas.

I can't thank the posters enough.
 
I have seen Glenn using his cooling device. Didn't know it was CO2. Just thought it was compressed air. Why wouldn't compressed air work as well or almost as well?

Donald
 
Compressed air will work just not as quick. The gas comes out much cooler than compressed air.
 
Any gas will work. It's called re expansion of a gas. It is the same as using a capillary tube cooling system. Like your refrigerator uses.

This system of cooling has only been around and in use since around 1850. The same effect is what makes a airplane fly (a wing to have lift) Pressure difference.

Hold on to a air nozzle and run air through it and you can feel the cooling effect.

A little know fact of history, our ancesors that coverd the great plains in covered wagons used this method to cool perashiable foods. These were known then, as icy balls, (no joke).:D

http://www.chemistry.wustl.edu/~edudev/LabTutorials/Thermochem/Fridge.html
 
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