How hot is too hot for a barrel?

[Eddie Harren]

THIS!

 

[Rustystud]

The temperature inside a barrel when fired 5,000 degrees at 55,000 -66,000 psi for 3 millionths of a second. Multiply that by 3000 rounds and you have less than 9 total seconds of barrel life.

 

[bobm]

My test was repeated with a couple of friends rifles some weeks later when we were shooting 60 shot silhouette matches. This was four 15 shot relays. The course of fire is 5 shots fired in 2 1/2 minutes with a 20- 30 second pause between sets of five targets. So, a total of 15 shots fired per relay in 8 1/2 minutes or less. Most shooters get them all out in 2 minutes per set with the 20-30 second pause in between. My friends .260 Rem. sporter reached 159-160 F at the 12th shot and remained that warm to the 15th. (he won the match even with six feet of thermo couple wire attached to his barrel). The results were about the same with another varmint weight .308 Win. This heat and cool cycle is repeated hundreds of times during the life of the competition barrel. They are not harmed and remain accurate until too much metal is eroded away.

 

[msinc]

Being able to hold my hand comfortably on the barrel is about right...as far as shooters getting hot, I have been hot out there shooting...but I have yet to burn out my throat so it's okay. Now rifles...I have cooked many throats in them.
I've made an M-60 glow once....Back in the early 80's when the M16A1 was the Army's weapon of choice we used to empty two 30 round mags in the hot summer {on full auto}, one right after the other without stopping and the rifle would start to have "cook offs". The third magazine, after a brief load/unload time would quickly have cook offs and if you set the rifle leaning against a wall the barrel would bend from so much heat. I don't do things like these days....cutting down trees with det cord is a walk on the wild side for me now!!! Or lighting up the farm with cluster stars...now that is fun.

 

[Brians356]

When you do let a rifle cool off, set it in the shade. Seems obvious, but I've seen guys do otherwise. And I always try to shoot from shade, to allow gun and shooter to heat up as slowly as possible, and reduce optical glare. After 40+ years in the high desert, I seem to have developed an aversion to direct sunlight. Shooting or hunting on a rare cloudy day is a real treat.
-

 

[Pawnee Bill]

What do you consider "slow fire"? I've got a half dozen rifles I've got to do ladder tests for and I'm concerned about overheating the barrels.

I don't know what the standard "time" is for slow fire. I shot 10 rounds in approx. 10-12 minutes I'm guessing.

 

[Pawnee Bill]

depends outside temp.here in ok it can get 110 in shade.then gun and shooter get hot.

I know, I live in Shawnee.

 

[ragsflh]

I know, I live in Shawnee.

rush springs

 

[6milphil]

I spent many, many summers in rush springs and fletcher as a kid, the humidity there is just plain wrong.

 

[dcali]

I don't know. I do know that velocity ticks up in as little as 10 shots or so at a normal slow fire (every 30 seconds or so) pace. That's not very hot.

Most people seem to be concerned about barrel life. Since barrel wear is a complex process involving phase change, cracking, and literal melting of the bore due to extremely high temperatures (thousands of degrees), I'm not sure it matters too much if the barrel starts out at 75 degrees or 175 degrees. You'd think cooler would be better, but it's not something I worry about.

 

[NorCalMikie]

If you can keep your hand on it without getting burned, it's not too hot.

 

[Nomad11]

Went shooting 6mm Remington yesterday trying some new loads at 200 yards and just happened to have my laser temperature gun with me. After shooting 10 rounds slow fire I checked the barrel temp at the throat area and it read 109 degrees and the end of the barrel read 107 degrees with OAT at about 90 degrees. This got me thinking about what the max temperature a barrel has to be before accuracy starts falling off. I've never seen any data on this. Has anyone done their own research to see what the magic temperature is?

I have a stick on thermometer (very cheap) on all my rifles and usually stop for 10 minutes or so when the temperature in front of the chamber hits 120 degrees F.

 

[T-shooter]

I have a stick on thermometer (very cheap) on all my rifles and usually stop for 10 minutes or so when the temperature in front of the chamber hits 120 degrees F.

60-90 seconds will cool it down using a high volume air pump blowing through the chamber. If the barrel is in direct sunlight, cover it with a towel.

 

[mike a]

The temperature inside a barrel when fired 5,000 degrees at 55,000 -66,000 psi for 3 millionths of a second. Multiply that by 3000 rounds and you have less than 9 total seconds of barrel life.

Sure makes the barrel nut design more appealing. DIY

 

[TheOtherZilla]

THIS!

Been there. Shot out 3-4 barrels in the NAM