Barrel heat up?

[garandman]

Is that really a thing? Where the barrel heats up and groups open up? If so, at what round count?

Was wondering what others were experiencing re: barrel heat up.

I expereinced some inaccuracy recently in rounds 25 - 30. Might be "heat up." Could also be (1) me / fatigue, laziness (2) different type of target aiming point for rounds 21 - 30.

Rounds 1 -20 has a very visible aiming point (blaze orange) 21 - 30 had a lime green aiming point. It was hard to see.

 

[buffybuster]

Rounds 1 -20 has a very visible aiming point (blaze orange) 21 - 30 had a lime green aiming point. It was hard to see.

That sounds like mirage from heat coming off the barrel. But groups opening up when the barrel gets hot from shooting is a real thing, depending on the quality of the barrel and residual stresses in it from the manufacturing process.

 

[Lunchbox27]

I've only had issues with hot barrels with factory options. My custom barrels all shoot the same (cold or hot). That said, I don't shoot more than 15 rounds (not rapid fire) before letting it cool for a while (20 mins or longer). Stand it up in the shade and it'll cool off quick.

Oh and bring more than 1 gun to the range. Makes waiting for the other barrel to cool easier.

 

[SonicBurlap]

Try these threads:

https://www.snipershide.com/shooting/threads/magnetospeed-barrel-cooler.6918102/#post-7723830

and

https://www.snipershide.com/shooting/threads/riflekuhl-cooling-systems.6939343/#post-7702404

 

[Greg Langelius *]

This and similar questions can be answered better if one knows the actual barrel temperature, at least as a factor for comparison against accuracy.

Your conclusions can only be as accurate as your data; so do your work with the real numbers.

This becomes both affordable and essential.

Greg

 

[garandman]

Try these threads:

This becomes both affordable and essential.

Greg

Thanx. Both of yous. I had *no* idea such things existed.

 

[Lunchbox27]

Try these threads:

https://www.snipershide.com/shooting/threads/magnetospeed-barrel-cooler.6918102/#post-7723830

and

https://www.snipershide.com/shooting/threads/riflekuhl-cooling-systems.6939343/#post-7702404

These work, but only if the temp outside is much cooler than the barrel itself. I have one of the first Barrel Cooler (yellow, and very loud) and I have the chamber chiller. I've used the Barrel Cooler for a few years, now. It works really well for cooling off suppressors, esp if you wanna move them faster from rifle to rifle. I have found that if you're out on a hot sticky day you're just pushing hot air through a hot barrel. But, you bring that temp down 20-30 degrees outside and you'll be surprised how fast these things can cool off not only your can, but a thick profile barrel in 2/3rd the time.

 

[SonicBurlap]

These work, but only if the temp outside is much cooler than the barrel itself. I have one of the first Barrel Cooler (yellow, and very loud) and I have the chamber chiller. I've used the Barrel Cooler for a few years, now. It works really well for cooling off suppressors, esp if you wanna move them faster from rifle to rifle. I have found that if you're out on a hot sticky day you're just pushing hot air through a hot barrel. But, you bring that temp down 20-30 degrees outside and you'll be surprised how fast these things can cool off not only your can, but a thick profile barrel in 2/3rd the time.

If you had those for a couple of years then it's time to upgrade, those were snails compared to a hare. Also on a hot day try to stand the rifle upright, if possible in the shade with the riflekuhl inserted and muzzle up so the hot air can escape while it is being expedited by the fan. I tried one of the old devices that weren't made by Magnetospeed and decided they weren't worth it, saw this one in use and was sold on it. They work well, especially, as you said if you are running a can.

 

[bourbonbent]

Steel physically changes when it heats up. It’s just part of steel, and matter for that matter.

Get any barrel hot enough and POI will shift, being improperly stress relieved (or no stress relief at all) will exacerbate this. A properly made, high quality barrel of suitable contour should not exhibit it, within reason.

For example, a 1.350” straight cylinder is gonna take a lot more to see a a POI shift due to heat than a factory rifle sporter taper. A sporter taper has far less mass, and will start to shift much quicker. A typical “tactical” or field taper is in between a truck axle and a soda straw, and should not show POI shift on a 20 shot string.

Here is a 10 shot string with a heavy Palma Bartlein in 308:

I mention chambering and all that, because this is also dependent on chambering. It will take a .222 much, much longer/more intense firing schedule to overheat a barrel and cause shift than say a Lazzeroni Warbird or a .505 Gibbs, etc.

As a general rule, the more powder being burned, and the faster the projo travels, the faster the barrel is going to heat up. We mitigate that by using a heavier barrel with more material surrounding the chamber and long hole to act as a heat sink. The larger surface area is also more efficient at dissipating the heat. This is why varmint contours are thicker than hunting contours, and why competition contours are even thicker in some instances, 20-30 shot strings where POI is extremely important to the end result.

 

[Lunchbox27]

If you had those for a couple of years then it's time to upgrade, those were snails compared to a hare. Also on a hot day try to stand the rifle upright, if possible in the shade with the riflekuhl inserted and muzzle up so the hot air can escape while it is being expedited by the fan. I tried one of the old devices that weren't made by Magnetospeed and decided they weren't worth it, saw this one in use and was sold on it. They work well, especially, as you said if you are running a can.

Sweet! Ill pick one of the MS’s up. I thought they were all the same. The Barrel Cooler is expensive to keep running. Uses Three 123 batteries and after 4-5 range days, its barely putting anything out.

 

[SonicBurlap]

The RifleKuhl only uses one 123 battery but as you said battery life on those is still 4-5 range days depending on usage in my experience, however a strong fan with one battery beats springing for three batteries every 4-5 days. I also like the fact that the neodymium magnet holds it secure in the chamber when I stand it up, and that the nozzle retracts so I can just clip it on my range bag without worrying about breaking it off.