Barrel cool down time?

[The Last American Hero]

Enhanced cooling sounds like a really really bad idea and great way to warp a barrel, since it will be cooling mostly just one section and causing all sorts of stress as that one part shrinks. Just because it didn't the last time doesn't mean it wont happen next time.

Brake rotors aren't warped by 'excessive braking'. They are warped when you have hot rotors, then suddenly leave the car parked and the pads prevent the part of the rotor they sit on from cooling at the same rate as rest of rotor.

Wet rags and Freez-Air both sound bad. Even if blasted down the barrel the Freeze will be hitting mostly one side with super freeze.

Under "Rate of Fire" most military rifles from bolt action to modern assault rifles are rated about "one rd/min sustained fire".

I used to open the bolt on my Mosins and carry them slung walking down to targets on the theory it would create a nice chimmey and gently but quickly cool them, until a bolt dropped and I spent about an hour searching the leaves and grass.


Only good solution IMO....enough guns to let them cool while you shoot the others, or at least load a few 22lr mags in mean time.


I had an idea of a clock spring driven shrouded fan inside the hand-guard of an AR style rifle. Every cycle would wind the spring a bit to max out at about 30rds, and then the fan would run for about 3 minutes after or constantly during heavy firing. Someone told me not to bother because accuracy not effected that much anyways and not an issue it that sort of use (army dudes spraying hella bullets). I still think its a neat idea. One more do-dad to put on a AR.

Heat sinks used on computer boards work really good, but IIRC they are quite expensive.

[JMP]

I have seen people do that, but believe it's very poor practice since it causes extreme temperature gradients in a non uniform way.

I am completely comfortable with a damp towel at ambient temperature. If you look at the specific heat of water and the temperature you'd be introducing it at, this would not really have any more effect than making contact with the barrel with your hand (A human hand will be about 310 Kelvin with similar specific heat to H20, and the H2O in a towel at STP will be ~298 Kelvin). Of course, I say damp, as the towel is porous, the thermal transfer will be lower. You will not be spiking the barrel temperature downward, you are just providing a medium for thermal energy to dissipate faster. It isn't that much different from natural ambient cooling, you just provide more particles, typically found in air (and the key is that the towel exists in the same TP state as the barrel), to more rapidly transfer thermal energy from the barrel.

Introducing a liquefied gas NOT AT STP, would be the concern--this rapidly cools a portion of the barrel well below it's natural ambient state until thermal energy is quickly transferred from another part of the barrel as steel has high thermal conductivity and will rapidly adjust as it tends to an equilibrium for the distribution of thermal energy.

Even so, my conjecture is that high quality steel barrels would probably not be harmed by this process, but I'd simply avoid it since there is no reason for it.

[The Last American Hero]

I am completely comfortable with a damp towel at ambient temperature. If you look at the specific heat of water and the temperature you'd be introducing it at, this would not really have any more effect than making contact with the barrel with your hand (A human hand will be about 310 Kelvin with similar specific heat to H20, and the H2O in a towel at STP will be ~298 Kelvin). .

Yes, professor, but you wont be leaving your moist hand on an uncomfortably hot barrel for an extended period of time while you futz around for a few minutes.

What I'm thinking is any cooling will be limited to no more than 212 because more than that will create a steam cushion, but I did crack a hot Lodge cast iron pan in half with the kitchen faucet.



PS-Didn't some clown de-skin his hand doing that "dip your hand in molten lead" trick, but instead of the lead being at 600? it was more like 1000? but looked "just like it did on TV" to untrained eye and also splattered because it was creating much more powerful "live steam".

[pacrat]

Being a hunter myself. And giving squat about how tight of a hot group my rifles will shoot. Light sporter hunting type barrels don't like heat. I allow 5 min. minimum between shots. With bolt open. I'm only interested in where EXACTLY shot #1 is going to land.

I use the time between shots to BS with other range goers and compare notes, anecdotes, and equipment.

JM2c

[JMP]

Yes, professor, but you wont be leaving your moist hand on an uncomfortably hot barrel for an extended period of time while you futz around for a few minutes.

What I'm thinking is any cooling will be limited to no more than 212 because more than that will create a steam cushion, but I did crack a hot Lodge cast iron pan in half with the kitchen faucet.

PS-Didn't some clown de-skin his hand doing that "dip your hand in molten lead" trick, but instead of the lead being at 600? it was more like 1000? but looked "just like it did on TV" to untrained eye and also splattered because it was creating much more powerful "live steam".

A damp towel is far from running it under a faucet where you continuously replace H2O molecules with less thermal energy.

By the way, I'd recommend not getting cheap factory made Chinese kitchenware. There may be other contaminants that can be hazardous. The exception is that you can get some of the best pans you can buy from China, but they are hand made by old school metal workers. My hand pounded pans ain't gonna crack under a faucet.

[Army]

Shoot your HUNTING rifle at the range, the same way you would in the field. If you know you will be shooting 3 rounds quickly at your quarry, shoot 3 rounds at the range...quickly.

Barrel heating is terribly misunderstood by most. Even if it just barely too hot to touch...it still is not hot enough to seriously change your impact BEFORE you fire a hunting spread of shots.

Any varmint shooter will tell you about hot barrels and point of impact. You have to shoot a LOT of ammo fast, before heat begins to do things. This is very difficult to do with any bolt action rifle, as the time between shots allows much of the heat to dissipate. I shoot dozens of rounds at squirrels before I worry about heat. Even then, I will wait about 15 minutes before going at it again (also gives me time to dig out a Dr Pepper from the cooler )

So, shoot paper like you hunt. If you need 5 fast shots at a deer or goat, are you seriously going to worry about a hot barrel at that moment?

[mwunsch]

Being a hunter myself. And giving squat about how tight of a hot group my rifles will shoot. Light sporter hunting type barrels don't like heat. I allow 5 min. minimum between shots. With bolt open. I'm only interested in where EXACTLY shot #1 is going to land.

I use the time between shots to BS with other range goers and compare notes, anecdotes, and equipment.

JM2c

Shot number 1. Yes sir. But I do have to shoot repeated "1st shot" groups to get this.

[Wrangler John]

Get y'all one of these, or something similar (Amazon has scads of them available) http://www.amazon.com/Non-Contact-In...ed+thermometer

I bought one of a similar design for less than $20 and use it to take temperature readings just ahead of the chamber. You can feel where the barrel is warmest and use that spot to sample. When shooting a 10 shot group for the chronograph I monitor the temperature and keep the barrel no warmer than 100 degrees F (depending on the ambient temperature). Remember that I am OCD about barrel break-in and overheating, but we all need a hobby.

[cocorador]

I'm very boring, I shoot 3 shots in between shooting sessions. In Livermore, that's 3 shots in 20 minutes. I can probably do more, but the anticipation may help me learn self control for when I'm in the field. I usually only shoot less than 15 rounds before I go home.