Cold bore zero versus (very) Hot bore zero “test”

[Chris in TN]

Extreme temperature gradients across a piece of metal, particularly if the outside is much colder than the inside, can cause the thermal stresses to exceed the yield stress, i.e. the metal ruptures. This is compounded if you are trying to simultaneously contain something that is very high pressure, the metal is very thick, and the temperature difference across the metal is large. The concerns guys are raising have roots in very real material science.

Those having success cold quenching hot barrels may be right that it is safe, long term in all circumstances, I'm not doing any math on the situation to prove otherwise. But there is a clear path to a material failure at the extreme limits of this approach.

Thermal Shock (Thermal Stress) | Engineering Library

This page provides the chapters on thermal shock (thermal stress) from the DOE Fundamentals Handbook.

engineeringlibrary.org

My understanding of thermal shock is that it would maybe, possibly be an issue if you'd mag-dumped your AR a few times in summer then sent it swimming.

But do note that this whole diversion started because Form suggested I put water on my muzzleloader barrel. The delta between a room-temperature bottle of water I might have in the barn in summertime and the internal temperature of the bore - when hot enough to cause issues with plastic sabots - would likely be well under 50 degrees. It takes almost nothing in terms of heat, to be a problem with soft muzzleloader sabots. It's a real pain in summer. Which is why I sometimes stick the things in my deep freezer. Also, I don't have running water in the barn, nor a drain if I were to pour it out. So I'll probably keep using the freezer. Muzzleloader load testing in summer isn't exactly a high-speed endeavor.

Gemini says you'd need to be at 450+F for it to be a problem. That's for barrels, not the can. I didn't ask about cans but I can see where a 3d printed Ti can might get hot enough to be a thing.

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[RME]

Extreme temperature gradients across a piece of metal, particularly if the outside is much colder than the inside, can cause the thermal stresses to exceed the yield stress, i.e. the metal ruptures. This is compounded if you are trying to simultaneously contain something that is very high pressure, the metal is very thick, and the temperature difference across the metal is large. The concerns guys are raising have roots in very real material science.

Those having success cold quenching hot barrels may be right that it is safe, long term in all circumstances, I'm not doing any math on the situation to prove otherwise. But there is a clear path to a material failure at the extreme limits of this approach.

Thermal Shock (Thermal Stress) | Engineering Library

This page provides the chapters on thermal shock (thermal stress) from the DOE Fundamentals Handbook.

engineeringlibrary.org

Those equations for stress in that article are for strictly constrained materials. What are the constraints to expansion for a barrel?

 

[ResearchinStuff]

Constrained is just one example of how thermal shock and material failure can happen. The material itself becomes a constraint when there is a temp gradient across the thickness such that the one boundary is heating up and expanding while the other is cooling and contracting.

 

[KyleR1985]

I deal with this in reverse the day job.

Water injection (100-300*) into steam piping (600-1170*). If the water isn’t atomized and hits steam pipe walls directly, constantly, you’ll see thermal cracking over time. The other issue is corrosion caused by condensate building up in that piping leading to cracking.

In this case you have to see inside the pipe to see the issue.

With a barrel it’s the opposite. If you’re causing cracks in the outside of your barrel, you’ll see them. Or can - dye will cause them to show up. It’s probably less than 20 bucks for someone to see if they’ve caused cracks in their barrel by pouring water on it or sticking it in the snow.


If the barrel has been stress relieved properly, I’m not sure how pouring water on the outside of it could have any impact on internal dimensions and surface texture. At least not with the amount of times someone could do it before shooting out a barrel.


I’m not betting the farm that you can’t make an accurate pressure containing barrel not be accurate or pressure containing by pouring water or snow on it. But I’d pay for the dye penetrant if someone wants to run a barrel beyond its useful life, and douse it with water every time it gets too hot to see to shoot.

 

[ResearchinStuff]

Yep, same phenomenon, except we are talking about 40F water or colder, and needing to contain 60,000 psi. Industries that are serious about keeping pressure vessels intact have heat up and cool down rate limits for a reason.

 

[journeyman713]

I think I actually shoot and know what happens, and you guess.

Form, haven’t seen you post anything in a while, must be a record.
Many of us are still waiting for you come clean on, “Exactly what happens, when you pour water on a smoking hot barrel and suppressor”. Outside of course, completely voiding the warranties.

---------------------

For those waiting, I’ll just add this.

Even though most of us are Hunters, on a Hunting forum, it’s important to recognize we’re not all on the same page, we are two different groups, with different goals. Both are fine, but different.

One group; Dreams of making that first shot count at Trophy game, they practice at ever expanding their ethical shot distance. Let’s call it the “One shot–one kill” camp. They tend to care for their equipment in a way, it could be passed down for generations.

The other group; Dreams of being knee deep in shell casings, then bragging about it as if it’s some measure of manhood, they believe, whoever shoots the most, wins. Let’s call them the “Gun–nuts” camp. They tend to do things in excess for fun, destroying their equipment, is just part of the game.

Very different goals.

So, when a member of the “Gun–nuts” camp makes a statement, often times it’s just about bragging, more to impress strangers than anything else, or maybe to start some ridiculous pissing match, no harm done.

But when they make suggestions… to the “One shot–one kill” camp… Remember, they don’t care about their equipment, and surely not about yours.
Such as, “just pour water on your Smoking hot barrel and Suppressor”. That guy definitely knows better, he just doesn’t care.

 

[MagnumHntr]

Form, haven’t seen you post anything in a while, must be a record.
Many of us are still waiting for you come clean on, “Exactly what happens, when you pour water on a smoking hot barrel and suppressor”. Outside of course, completely voiding the warranties.

---------------------

For those waiting, I’ll just add this.

Even though most of us are Hunters, on a Hunting forum, it’s important to recognize we’re not all on the same page, we are two different groups, with different goals. Both are fine, but different.

One group; Dreams of making that first shot count at Trophy game, they practice at ever expanding their ethical shot distance. Let’s call it the “One shot–one kill” camp. They tend to care for their equipment in a way, it could be passed down for generations.

The other group; Dreams of being knee deep in shell casings, then bragging about it as if it’s some measure of manhood, they believe, whoever shoots the most, wins. Let’s call them the “Gun–nuts” camp. They tend to do things in excess for fun, destroying their equipment, is just part of the game.

Very different goals.

So, when a member of the “Gun–nuts” camp makes a statement, often times it’s just about bragging, more to impress strangers than anything else, or maybe to start some ridiculous pissing match, no harm done.

But when they make suggestions… to the “One shot–one kill” camp… Remember, they don’t care about their equipment, and surely not about yours.
Such as, “just pour water on your Smoking hot barrel and Suppressor”. That guy definitely knows better, he just doesn’t care.

You never answered my question either....

Lets all move on since it seems you just want to argue with Form.

 

[WhoGarrDen]

Form, haven’t seen you post anything in a while, must be a record.
Many of us are still waiting for you come clean on, “Exactly what happens, when you pour water on a smoking hot barrel and suppressor”. Outside of course, completely voiding the warranties.

---------------------

For those waiting, I’ll just add this.

Even though most of us are Hunters, on a Hunting forum, it’s important to recognize we’re not all on the same page, we are two different groups, with different goals. Both are fine, but different.

One group; Dreams of making that first shot count at Trophy game, they practice at ever expanding their ethical shot distance. Let’s call it the “One shot–one kill” camp. They tend to care for their equipment in a way, it could be passed down for generations.

The other group; Dreams of being knee deep in shell casings, then bragging about it as if it’s some measure of manhood, they believe, whoever shoots the most, wins. Let’s call them the “Gun–nuts” camp. They tend to do things in excess for fun, destroying their equipment, is just part of the game.

Very different goals.

So, when a member of the “Gun–nuts” camp makes a statement, often times it’s just about bragging, more to impress strangers than anything else, or maybe to start some ridiculous pissing match, no harm done.

But when they make suggestions… to the “One shot–one kill” camp… Remember, they don’t care about their equipment, and surely not about yours.
Such as, “just pour water on your Smoking hot barrel and Suppressor”. That guy definitely knows better, he just doesn’t care.

I have never seen what you are describing in terms of "two camps", and I think you're just trying to stir the pot. You're using a handful of people to define an entire group and painting in broad strokes to cause division like you're in some kind of political race and running for Thread Mayor.

Multiple people have commented on the hot barrel + water topic, many with some decent science or anecdotes, but because one poster hasn't responded to your prodding in less than 24 hours, this is how you respond to the forum as a whole...

I've used the water bottle trick on my barrel and Harvester Evo and haven't seen any signs of accuracy issues - I like the idea of the dye test mentioned previously and would be interested to see what a few of these extremely abused barrels really look like. Maybe we will find certain manufacturers/processes/contours may need babying, but probably not.

 

[Axlrod]

Simple question, what makes it a bad idea?

It is marbles, as in I have lost my marbles.

Marble is another poster (as in he is as solid as marble). People get the two mixed up, and for the sake of Marble, I feel the need to clarify. For myself, I answer to any 4 letter word.

Well to clarify a little more. He called you Mabel, not Marbel, Marbels.

 

[atmat]

Form, haven’t seen you post anything in a while, must be a record.
Many of us are still waiting for you come clean on, “Exactly what happens, when you pour water on a smoking hot barrel and suppressor”. Outside of course, completely voiding the warranties.

---------------------

For those waiting, I’ll just add this.

Even though most of us are Hunters, on a Hunting forum, it’s important to recognize we’re not all on the same page, we are two different groups, with different goals. Both are fine, but different.

One group; Dreams of making that first shot count at Trophy game, they practice at ever expanding their ethical shot distance. Let’s call it the “One shot–one kill” camp. They tend to care for their equipment in a way, it could be passed down for generations.

The other group; Dreams of being knee deep in shell casings, then bragging about it as if it’s some measure of manhood, they believe, whoever shoots the most, wins. Let’s call them the “Gun–nuts” camp. They tend to do things in excess for fun, destroying their equipment, is just part of the game.

Very different goals.

So, when a member of the “Gun–nuts” camp makes a statement, often times it’s just about bragging, more to impress strangers than anything else, or maybe to start some ridiculous pissing match, no harm done.

But when they make suggestions… to the “One shot–one kill” camp… Remember, they don’t care about their equipment, and surely not about yours.
Such as, “just pour water on your Smoking hot barrel and Suppressor”. That guy definitely knows better, he just doesn’t care.

This is such a poor take. I don’t know when Form hurt your feelings, but I’d just drop it amigo. Go shoot guns and let them cool at whatever rate you want. No one is forcing you to waterboard your barrel or suppressor.

 

[WyldGoose]

Form, haven’t seen you post anything in a while, must be a record.
Many of us are still waiting for you come clean on, “Exactly what happens, when you pour water on a smoking hot barrel and suppressor”. Outside of course, completely voiding the warranties.

---------------------

For those waiting, I’ll just add this.

Even though most of us are Hunters, on a Hunting forum, it’s important to recognize we’re not all on the same page, we are two different groups, with different goals. Both are fine, but different.

One group; Dreams of making that first shot count at Trophy game, they practice at ever expanding their ethical shot distance. Let’s call it the “One shot–one kill” camp. They tend to care for their equipment in a way, it could be passed down for generations.

The other group; Dreams of being knee deep in shell casings, then bragging about it as if it’s some measure of manhood, they believe, whoever shoots the most, wins. Let’s call them the “Gun–nuts” camp. They tend to do things in excess for fun, destroying their equipment, is just part of the game.

Very different goals.

So, when a member of the “Gun–nuts” camp makes a statement, often times it’s just about bragging, more to impress strangers than anything else, or maybe to start some ridiculous pissing match, no harm done.

But when they make suggestions… to the “One shot–one kill” camp… Remember, they don’t care about their equipment, and surely not about yours.
Such as, “just pour water on your Smoking hot barrel and Suppressor”. That guy definitely knows better, he just doesn’t care.

The idea that your “gun-nuts camp” just wants to stack piles of shell casings and brag about manliness to strangers might just be your perception. The main point being that the more you shoot, the better you get and the chances of success increases, while mistakes decrease.
Most the folks I’ve been around my entire life are in your “one-shot-one-kill camp”. Boomers who baby their equipment that hardly ever gets used, and I’ve witnessed so many shit show rodeos that could’ve been avoided had they spent a little more time mentally in the other camp.
Rokslide is a place that encourages folks to practice, shoot more, adopt more efficient systems and not worry about things that don’t matter. The funny part is the amount of resistance to that advice that gets posted by dudes who feel like there’s some other camp they’re not welcome in because their old system is criticized as less effective.

 

[KyleR1985]

Yep, same phenomenon, except we are talking about 40F water or colder, and needing to contain 60,000 psi. Industries that are serious about keeping pressure vessels intact have heat up and cool down rate limits for a reason.

Don’t disagree - I’m not saying these two things are exactly the same.

Temperature differential of that thermal shock remains the same going from 40-800 or so(my redneck cowboy guess at a hot barrel temp), or 300*-1100*. In fact most of the damage I see in these systems are when customers refuse to change water source for steam cooling from ambient temperature condensate to heated feedwater(300*). They’re going from ambient (0-100*) to 1150, constantly.

These pipes don’t blow up and kill people suddenly. It’s a long process, and the systems are in place to find it prior to getting bad enough. It just costs millions of dollars that we end up footing the bill for because our power providers don’t care.

But a barrel has a few things going for it compared to high pressure steam piping:

- Wall thickness is usually something like 50-70% of bore diameter, and way higher at chamber - most high pressure steam piping systems we’re talking about here are going to be in the 12-15% range.

- pressure is momentary - that 60k psi is for an instant. High pressure piping and vessels remain under constant pressure.

- pressure has somewhere to go with less resistance - each end of the barrel is open - pressurized media is going to take path of least resistance. The amount of expansion of the pressurized media is going to be incredible for flow to the two ends of the barrel to get choked in a way that expanding or cracking the barrel itself offers less resistance. Pressurized piping does have a beginning and end. But it’s so far from the spot you’re measuring pressure, and it’s constant, these can’t be compared.

- the thermal cracks are occurring in steam piping when they’re either pressurized or under vacuum. Not when systems are depressurized. Leaving the water cooled machine gun aside, we’re dumping water on a barrel when it’s not under pressure.

- we’re pouring water on the “cold” side of the barrel. Water injection is occurring on the “hot” side of the high pressure steam piping. Small difference probably but could be huge difference in cold temps.


Again, I’m not advocating any action here. But I do think there’s quite a bit of evidence to suggest that putting water on the outside of a hot barrel is not going to have any material effect on its pressure containing capabilities. Accuracy impact I’m more open to - though still skeptical.

 

[Chris in TN]

Hey, Google, how hot is that barrel getting, anyway?

Google Search

 

[Chris in TN]

Cliff notes: We are making much ado about absolutely nothing:

 

[elkguide]

 

[Bluumoon]

Yep, same phenomenon, except we are talking about 40F water or colder, and needing to contain 60,000 psi. Industries that are serious about keeping pressure vessels intact have heat up and cool down rate limits for a reason.

I’ve certainly thought about messing up a barrel by running it under cold water whilst hot so that I can continue shooting a 20 round group without mirage. Then I decided screw it, let’s see what happens, that was a while ago. Maybe less extreme temps compared to what others are doing, ie shoot until I see mirage (mostly from suppressor) hit the exterior with cold water, repeat.

 

[Gstew1930]

This doesn't seem that complicated to me, if Form says something crazy or you think is stupid, test it & prove him wrong. I've been testing shit he says for awhile now with the hope I can catch that MF slipping lol. its coming

 

[KyleR1985]

Looks like 200 rounds a minute can tear one up!

 

[RME]

This doesn't seem that complicated to me, if Form says something crazy or you think is stupid, test it & prove him wrong. I've been testing shit he says for awhile now with the hope I can catch that MF slipping lol. its coming

Exactly! Don’t like it? Test it. The rest of the what ifs” in this thread have completely gone off the rails

 

[Marbles]

Well to clarify a little more. He called you Mabel, not Marbel, Marbels.

Well, apparently neither of us can read, because he wrote 'Mable' and my brain inserted an r and yours reversed the e and the l.

But you make a good point, I don't think Mable posts on RS, so no need to correct anyone.