Barrel temperature
- Thread starter cw308
- Start date
The reason I asked the question, we all are trying not to shoot with our barrel overheating. I installed a temperature sensing label to my barrel from 86 to 140 . Will see how it works this weekend. To see when it's time to cool down. I'm a bench rest shooter, take time between shots but really didn't know when warm was to warm. Will get back after my shooting this Sunday.
FrankenMauser
New member
It depends upon the barrel.
One of my .270 Win rifles will start stringing shots high, right as the barrel approaches about 100 degrees F. (Hammer-forged barrel with poor action bedding.)
But, I have several other rifles (primarily button-rifled) that maintain accuracy even when the barrel is too hot to touch (~140+ F). If I continue to fire them when they're scorching hot, then I increase the chance of premature throat erosion ...but they do maintain accuracy.
Though none are benchrest rifles, nearly every rifle that I own has been subjected to an impromptu "I wonder what this barrel does when it gets hot"-test. ....And that's how I found out how hot is too hot, for each rifle.
For the most part, and nearly always when testing loads during the winter, I actually try to keep a little heat in the barrel. In the winter, I hover around 60-70 F (feels good on cold hands between strings). In the summer, it's whatever I can manage in the shade - 70 F, 80 F, 90 F...
One of my .270 Win rifles will start stringing shots high, right as the barrel approaches about 100 degrees F. (Hammer-forged barrel with poor action bedding.)
But, I have several other rifles (primarily button-rifled) that maintain accuracy even when the barrel is too hot to touch (~140+ F). If I continue to fire them when they're scorching hot, then I increase the chance of premature throat erosion ...but they do maintain accuracy.
Though none are benchrest rifles, nearly every rifle that I own has been subjected to an impromptu "I wonder what this barrel does when it gets hot"-test. ....And that's how I found out how hot is too hot, for each rifle.
For the most part, and nearly always when testing loads during the winter, I actually try to keep a little heat in the barrel. In the winter, I hover around 60-70 F (feels good on cold hands between strings). In the summer, it's whatever I can manage in the shade - 70 F, 80 F, 90 F...
As stated, if you can't hold your hand on the barrel, it's too hot.
Here's a personal experience from a public range in Colorado in 2010: We went to check the zero on our muzzleloaders but found the firing line crowded and sat back to wait and watch. A young guy on the end of the firing line was blasting away with an obviously new rifle like he was repelling zombies. He'd fire 3-5 shots and fiddle with his "el-cheapo" Chinese tacticool scope and shoot some more. I shuffled over to see what he was actually doing.
Shooting at a large paper target at 50 yards, he was trying to "zero" his new rifle/scope set-up. The Rem 700 in 30/06 was pounding him significantly so his 50 yard groups were about 3-5" and fairly random. During a firing break, he asked me to check his rifle for obvious problems since he was almost out of ammo(3 boxes) and still wasn't anywhere close to a good zero. When I picked the rifle up my index finger touched the barrel and the metal actually burned me. Fortunately, it wasn't my trigger finger. I pointed this out and the guy's answer was to pour water on the barrel from the water bottle he was drinking from. This was the first time I'd seen a bolt action bolt and receiver hot to the touch. The synthetic stock's forend seemed kind of soft and squishy. I suggested he save the rest of his ammo and go look for a better scope.
Here's a personal experience from a public range in Colorado in 2010: We went to check the zero on our muzzleloaders but found the firing line crowded and sat back to wait and watch. A young guy on the end of the firing line was blasting away with an obviously new rifle like he was repelling zombies. He'd fire 3-5 shots and fiddle with his "el-cheapo" Chinese tacticool scope and shoot some more. I shuffled over to see what he was actually doing.
Shooting at a large paper target at 50 yards, he was trying to "zero" his new rifle/scope set-up. The Rem 700 in 30/06 was pounding him significantly so his 50 yard groups were about 3-5" and fairly random. During a firing break, he asked me to check his rifle for obvious problems since he was almost out of ammo(3 boxes) and still wasn't anywhere close to a good zero. When I picked the rifle up my index finger touched the barrel and the metal actually burned me. Fortunately, it wasn't my trigger finger. I pointed this out and the guy's answer was to pour water on the barrel from the water bottle he was drinking from. This was the first time I'd seen a bolt action bolt and receiver hot to the touch. The synthetic stock's forend seemed kind of soft and squishy. I suggested he save the rest of his ammo and go look for a better scope.
reynolds357
New member
With the exception of a couple of rifles I used to use in 1k shooting, I have never had a problem overheating a benchrest rifle. Normal Bench rest cartridges and courses of fire are not going to overheat the rifle. When 1k shooting was in its infancy and everybody shooting thought we had to shoot a boomer, then overheating was an issue. We quickly learned that the obnoxious powder burners were not necessary for 1k shooting.
I have shot NRA across the course in all weather conditions. In very cold, such as Dec, Jan, weather, I have been grateful to wrap my cold fingers around the barrel after a rapid fire string. Ten rounds fired in 60 or 70 seconds will just make the barrel warm, but not scalding hot.
I never shot much rattle battle, but I was told by guys who did, the rapid fire involved quickly ate up barrels.
I never shot much rattle battle, but I was told by guys who did, the rapid fire involved quickly ate up barrels.
IMO, the first answer is the right one.
Second one, I'm not so sure that it's always relevant.
Bull contour barrels aren't going to string much if at all, even when somewhat hot. However, I do believe throat life is an issue here with "relative" barrel burners- where throat erosion will accelerate as the heat in the leade gets to unacceptable levels. I think there's two issues- accuracy, and potentially accelerated wear to the barrel.
DesertRatR
New member
How hot before a barrel is permanently ruined?
winchester1917
New member
Wouldn't barrel contour dramatically effect the dependability of this method of testing? I.E. The surface temperature of a light contour barrel would be close to the temperature of the bore/throat of the barrel, whereas the surface of a heavy/bull barrel would have a greater difference in temperature, relative to the bore/throat, due to much greater mass absorbing heat before it manifests itself on the outside of the barrel.
Someone straighten me out...
Hard to get there unless you shoot fully auto.
I had access to some temperature indicating tapes a couple years back. After 2 strings of rapidfire (10rds each in 60 sec with maybe a minute or two between) through an M1A Supermatch. The barrel reached 170F. The typical heavy match barrel will run either 4-6 or 6-8k rds depending on how its made (button vs cut rifling). Somewhere at that point, you'll start to see 600yd groups open up, although it will continue to run fine for much much longer at short range.
I think most people are overly preoccupied with barrel temperature. As long as your not dumping mags continuously downrange, you're probably not being overly abusive. Yeah, you could probably pick up something on the order of a 20% improvement. But consider that most barrels are going to exceed the lifetime of the owner, and are more likely to die of neglect than being shot out. So if the rifle will take the heat, I will continue to fire at my pace.
Now on one of the barrel burning calibers (22-250, 243 sort of things), you might consider choosing a more leisurely rate of fire.
The heavier barrel will have a higher heat capacity and will take longer to heat up. But heat will move pretty quickly through the metal in either case--so the temp drop between the bore and the outside isn't all that significant until you get into honest sustained fire (continuous mag dumps). If the wall thickness was say over an inch, then it may be another matter. For heat transfer purposes, the our barrels are comparatively thin, regardless of profile.
The heavier barrel will be cooler during firing, but that's because it has a greater thermal mass. Similarly, it takes longer for the heavy barrel to shed its heat.
winchester1917
New member
^ makes sense. So the hand-on-barrel test is good for bench/target shooting, but not quite as reliable when one is just trying to see how many projectiles he can get in the air simultaneously...
The heat sensing label worked great. After speaking to my range friends & asking them the same question, everyone said the same thing, by touching the barrel. Once I showed them the label they all gave it a try. When the label is between 113 & 122 it's time to let the barrel cool down. How well I shot, well let's say the label worked well. We'll save that one for another post. How to keep your attention on your groups & not on your sensing label.
With my rifle I have found that an exact temp of what is too hot is impossible to find. I use a cheep infrared thermometer to keep an eye on my temps. The change in bullet impact is where I let her cool down. last trip to the range I played with barrel temp a little. 5 consecutive shots and impact shifts up and right. If I set the timer on my phone to 2min45sec I get cold bore shots every time. I guess what I'm trying to say is that the barrel never hit an exact temp when the impact changed but given a consistent rest period I could maintain the "cold bore shot". I have tried this in july at 90f and now in nov at 40f ambient air temp, the barrel had all sorts of different temp readings. obviously the cooler air temp cools the barrel faster than 90f and humid, but the rest time stayed about the same to get back to cold bore, out of the case 1st shot accuracy. With that said if I fire a couple of warmup shots and account for the drift of my bullet impacts I can shoot all day and keep a 3" group @200m no matter the temp. I've gotten my 5.56 to 188f with no issue and my 308 too hot to hold the rifle by the barrel or see through the scope at 22x with all the heat shimmer coming off the barrel.
well that's my 2cents.
well that's my 2cents.