Barrel heat

[Ranger188]

The Forum Boss posted an article about measuring barrel heat in the Daily Bulletin.
What is too high or hot at the point you need to let it cool down or wait a couple
minutes?
Has anyone done a test for this?

 

[K22]

I don't know about any "tests" but some shooting disciplines require some level of sustained fire. It's part of the sport. You can minimize the effects by using a milder cartridge if it's competitive but replacing barrels for sustained fire competition is just part of the process in competing in that sport.

I'm primarily a varmint (eastern ghogs) and predator hunter so my rifles do not see a very much sustained fire and when they do, it's usually only two rounds. During range practice, I do not shoot out of a hot barrel since my primary interest is the cold barrel shot, i.e. the "money shot". I'm fortunate because I'm retired and I can spend time at the range and shoot cold to cool barrel shots only. Typically, my range practice consists of 10 to 12 rounds fired over a one to one and half hour range session.

I see guys at the range shooting sustained fire in heavy calibers in bolt action rifles when there is not reason for it that I can see. The barrels become so hot you can even touch them. This can easily be avoided and should be but hey, if you like to make a bunch of noise and that's your thing then go for it but don't expect to get long barrel life. However most of these "noise makers" aren't interested in precision shooting. I'm not sure what their interested in except they enjoy shooting fast.

As far as judging the temperature of the barrel, I just use the old 'hand' test. On cool days I can get a cool barrel shot with only about 5 minutes wait time. On hot days, 90's, it sometimes takes 10 minutes or so depending on the contour of the barrel. Of course this can vary widely depending the cartridge intensity. I don't know that you need fancy devices to assess when the barrel is too hot or that's there is some magical temperature number. I try to simulate field conditions during my range practice.

I do believe heat is the greatest enemy of barrel life so excessive heat should be avoided if and when possible.

 

[djporter]

McMaster Carr has temperature strips that stick on the barrel. Very handy to keep a eye on your barrel temperature.

 

[bobm]

I did a test a decade ago measuring barrel temperature at a silhouette match. Some shooters had barrel heat concerns about firing a 60 shot match with 15 shot strings. I attached a thermo couple leade wire about mid length on a sporter weight 7mm-08 stainless barrel. A Fluke digital thermometer recorded the temp increase for each of the 15 shots I fired. I fired a shot every 30 seconds representing the time allotted for a timed string of shots.

At shot #10 the reading was 152 F with shots 11 thru 15 only adding another 9 degrees. Final peak temp at the 15th shot was 161 degrees F.

The barrel cooled to the ambient air temperature of 92 F in only 12 minutes with just a light breeze present.

 

[thestoicmarcusaurelius]

You guys make me feel like I abuse my barrels lol

what about 30 shots in five minutes lol

 

[D-4297]

I shoot TR ; and I try to practice with four or five sighters , and 20 shots for record within 18 minutes , and on some warm days , the barrel does get hotter than I'd like it to . Unless you're shooting at the north pole , I might consider 30 / five as barrel abuse . But Hey ....It's your barrel .

 

[Fast14riot]

I did a test a decade ago measuring barrel temperature at a silhouette match. Some shooters had barrel heat concerns about firing a 60 shot match with 15 shot strings. I attached a thermo couple leade wire about mid length on a sporter weight 7mm-08 stainless barrel. A Fluke digital thermometer recorded the temp increase for each of the 15 shots I fired. I fired a shot every 30 seconds representing the time allotted for a timed string of shots.

At shot #10 the reading was 152 F with shots 11 thru 15 only adding another 9 degrees. Final peak temp at the 15th shot was 161 degrees F.

The barrel cooled to the ambient air temperature of 92 F in only 12 minutes with just a light breeze present.

I would think taking temp readings at the chamber area would be more conclusive since throat erosion is directly related to barrel temp at the throat, and barrel wear happens from the throat forward.

 

[243winxb]

Heat can make some barrel walk. Bullet impact will move out of the group. I have 2 factory barrel that walk.
Take 20 rounds and fire fast as a test.

The military test shows heat can kill a barrel. https://discover.dtic.mil/

 

[thestoicmarcusaurelius]

I shoot TR ; and I try to practice with four or five sighters , and 20 shots for record within 18 minutes , and on some warm days , the barrel does get hotter than I'd like it to . Unless you're shooting at the north pole , I might consider 30 / five as barrel abuse . But Hey ....It's your barrel .

sometimes you're on your lunch break and you've got 30 rounds loaded up and the range is 10 minutes away and you just go for it ... LOL

 

[ebb]

Bob M all the damage is done in the lead and throat , just ahead of the chamber.

 

[Fuj]

I keep a laser temp gun in my range bag. Real cheap from
'Horror Fright". Usually use it quite a bit for those long
strings, in a case forming session. Headed to the range
today for just that purpose. I shoot the real deal when
forming. The Cream of Wheat guys probably experience
no heat at all.

My old Ruger 270 would print a perfect frown when getting
hot. Always went high and right.

 

[bobm]

Bob M all the damage is done in the lead and throat , just ahead of the chamber.

Sir, I am well aware of this. But when a guy says that his barrel is getting too hot, he usually touches the muzzle end to determine this. I was able to demonstrate that the five additional shots did not raise the surface temperature much more than a normal 10 shot string. The leade wire placement was right where I wanted it.

 

[Straightshooter1]

The Forum Boss posted an article about measuring barrel heat in the Daily Bulletin.
What is too high or hot at the point you need to let it cool down or wait a couple
minutes?
Has anyone done a test for this?

The way see it, what is too hot varies from caliber to caliber. For my .308, I've found it's best to not let my barrels get over 122 deg. F. When ambient temperatures are less that 80 deg. F with my typical rate of fire on my bolt gun, I seldom get to that limit, even with hot loads. Of course, the higher the temperature the faster the barrel heats up and the slower it cools down. Here in Arizona summers, it can take quite a long time too cool down naturally, so using chamber fans or other means is necessary to speed up the process. In order to keep track of the heat, I use a temperature label attached to the barrel near the action and with a quick glance I can see where the temperature of the barrel is.

Amazon.com: Digi-Sense Reversible 7-Point Horizontal Temperature Label Black/Red, 30-60C/86-140F; 10/Pk : Industrial & Scientific

Amazon.com: Digi-Sense Reversible 7-Point Horizontal Temperature Label Black/Red, 30-60C/86-140F; 10/Pk : Industrial & Scientific

www.amazon.com

 

[Ranger188]

I just wondered if say 150 or 180 was at the point that the barrel would see some permanent
damage if sustained at that temp. for very long.
I would think one of the barrel makers would have done some testing on this.
If they would tell you this, then you could possibly prolong your barrel life.
I know a lot of other things come in to play that produce heat.

 

[SmokinJoe]

Old rule of thumb is that if it's too hot to hold, it's too hot. I use the temp strips on my PD rifles on the chamber end, and try to hold it to 120 degrees F max.

 

[ballisticxlr]

I just wondered if say 150 or 180 was at the point that the barrel would see some permanent
damage if sustained at that temp. for very long.
I would think one of the barrel makers would have done some testing on this.
If they would tell you this, then you could possibly prolong your barrel life.
I know a lot of other things come in to play that produce heat.

The problem with this kind of thinking is it's applying a discontinuous mindset to a continuous process. Throat wear is a continuous process which is aggravated by increases in temperature. It's not that it's sustaining damage after some magical temperature point. It's how much damage is it sustaining at tempX compared to tempY on a per shot basis and how much that grows with temperature. The barrel is always taking some damage with every shot but shot to shot is essentially unmeasurable. Get a barrel 1 degree hotter than any arbitrary point and it will take more damage per shot, just probably not measurably more. The military did formal studies, heat kills pipes. The rule of thumb is about the best we have because you have to accept some barrel heat or no kind of match shooting will get very far and plinking would be declared evil (I'm looking cross eyed at those guys that mag dump into dirt right now).

 

[PhilC]

I keep a laser temp gun in my range bag. Real cheap from
'Horror Fright". Usually use it quite a bit for those long
strings, in a case forming session.

What I do as well except for brand.

 

[INTJ]

I keep a laser temp gun in my range bag. Real cheap from
'Horror Fright". Usually use it quite a bit for those long
strings, in a case forming session. Headed to the range
today for just that purpose. I shoot the real deal when
forming. The Cream of Wheat guys probably experience
no heat at all.

My old Ruger 270 would print a perfect frown when getting
hot. Always went high and right.

Not sure about the Cream of Wheat guys other than they have a mess to clean up.

To fire form 6 BRA rounds in my Light Gun I use 20 grains of Bullseye and 1/8 piece of toilet paper. The barrel gets extremely hot.

The last time I fire formed 200 rounds this way I borescoped the barrel (new) afterward with my Hawkeye. There was no throat erosion and only a light gray haze that quickly cleaned up. So it more than just heat.

 

[jelenko]

I think it depends on what you use your rifle for.
In competitive shooting you go at the pace of the match and practice at the same pace - barrels are consumables. For example, in 'cross the course', many matches have four 10 shot strings that are each shot within ~ 1 min. Two of those strings could be shot within a few minutes of the previous one. On hot days, the barrels are too hot to touch - there's no place for chamber fans.

 

[bobm]

Not sure about the Cream of Wheat guys other than they have a mess to clean up.

To fire from 6 BRA rounds in my Light Gun I use 20 grains of Bullseye and 1/8 piece of toilet paper. The barrel gets extremely hot.

The last time I fire formed 200 rounds this way I borescoped the barrel (new) afterward with my Hawkeye. There was no throat erosion and only a light gray haze that quickly cleaned up. So it more than just heat.

Yes, part of the erosion process comes from flaming kernels of propellant impacting and abrading the steel under high pressure and velocity. The powder charge is not entirely consumed in the brass case.