Boyd Allen
Active member
I think that Dennis has asked an interesting question. If the barrel never gets hot in the first place, will this happen?
jackie schmidt
New member
Boyd
What about places such as Midland, and Phoenix, where 7 percent humidity can be the norm??.......jackie
What about places such as Midland, and Phoenix, where 7 percent humidity can be the norm??.......jackie
"Heat".........What exactly is "heat"???
Temperature differential? Energy transfer?
A barrel setting out in the sun on a warm day gets hotter than my barrel does shooting 7-8 rds on a 50* day.......but a WARM barrel on a COOL day would indicate a "dewpoint" in the barrel, or would it? I'm intrigued by all this "water in the bore" stuff (Bill ain't the only one telling it)
I allus get moisture on my cold drink not on my coffee cup..........
al
Temperature differential? Energy transfer?
A barrel setting out in the sun on a warm day gets hotter than my barrel does shooting 7-8 rds on a 50* day.......but a WARM barrel on a COOL day would indicate a "dewpoint" in the barrel, or would it? I'm intrigued by all this "water in the bore" stuff (Bill ain't the only one telling it)
I allus get moisture on my cold drink not on my coffee cup..........
al
M
Mike Marcelli
Guest
Boyd
If you liked Dennis' questions, how about these?
1. What are the byproducts of nitrocellulose combustion? (Hint: They are the same byproducts as any organic (CH) compound with the addition of (NOx))
2. At what static temperature does water desorb from stainless steel?
3. When you add a lubricant to the bore, does the velocity increase or decrease?
If you answer these questions, and have an understanding of how a chemical reaction is initiated and/or maintained, you'll be able to figure out whether or not water or heat is the culprit that causes the velocity increase we see when a round cooks in the chamber.
If you liked Dennis' questions, how about these?
1. What are the byproducts of nitrocellulose combustion? (Hint: They are the same byproducts as any organic (CH) compound with the addition of (NOx))
2. At what static temperature does water desorb from stainless steel?
3. When you add a lubricant to the bore, does the velocity increase or decrease?
If you answer these questions, and have an understanding of how a chemical reaction is initiated and/or maintained, you'll be able to figure out whether or not water or heat is the culprit that causes the velocity increase we see when a round cooks in the chamber.
D
Dennis Sorensen
Guest
Maybe you are missing the point I am trying to make...
...eliminate the condition whether there is moisture in the barrel ... and then tell me that one round heated quite hot with resulting higher pressure and higher velocity will shoot "in" the group with the other rounds that are not heated up?
***desorb - go away from the surface to which (a substance) is adsorbed.
Stainless barrels absorb water?
M
Mike Marcelli
Guest
Well, the technical term is adsorb, but yes. Practically every substance you can imagine adsorbs water: glass, steel, ceramics, and teflon to name a few. Adsorption is actually the creation of a chemical bond between the material and water. It's quite a difficult bond to break. Until enough energy (heat) is introduced into the substrate (steel, glass, etc.) the water remains attached to the substrate and the ratio of water to substrate remains unchanged.
Your questions are good ones and I'll send you a PM answering them, but, I don't want to give away the answers yet.
Boyd Allen
Active member
Mike,
That last part about "..,I don't want to give away the answers yet." Almost sounds like Bill.
Boyd
That last part about "..,I don't want to give away the answers yet." Almost sounds like Bill.
Boyd
jackie schmidt
New member
Bill Marcelli???
Sorta has a ring to it........jackie
Sorta has a ring to it.
.......jackie
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Mike Marcelli,
I’ve always believed that thin turned necks are a desirable thing because if there is a difference in the brass, the bullet grip should see a smaller percentage of that difference. Like trying to sort rubber bands based on feel when one pile is very thick and the other pile is very thin.
That thought will appear off-topic to some until I ask how the friction reduction given by water vapor in a SS barrel, compares to water vapor in a moly coated barrel shooting moly coated bullets.
TIA
Jim
I’ve always believed that thin turned necks are a desirable thing because if there is a difference in the brass, the bullet grip should see a smaller percentage of that difference. Like trying to sort rubber bands based on feel when one pile is very thick and the other pile is very thin.
That thought will appear off-topic to some until I ask how the friction reduction given by water vapor in a SS barrel, compares to water vapor in a moly coated barrel shooting moly coated bullets.
TIA
Jim
K
Kathy
Guest
Friend Dennis
Friend Dennis:
I had about 50 things to do today....40 of them is done....10 to go....man, I'd give anything if I wasn't so lazy.......but, I've been like this all my life so it's hard to change.......
Dennis, back some posts ago, man, I hate these big old nasty threads, you asked some questions........one was something like, how quick does condensate form in the bore after a round has been fired...
You ever bring a rifle inside, during winter, that was left in the trunk of you car.........as soon as you enter the heated house, that shinny, polished barrel turns frost gray.....with condensate.....
This is an extreme example, but, the exact same thing happens after we fire one round through our barrel.....as soon as the bullet exits the muzzle, condensate starts forming.......
My friends, I started this thread to discuss how to determine if we have our muzzle stopped.....man, I simply can't believe that the centerfire benchrest community doesn't understand the "cooked round" problem....I'm sorry, no disrespect intended....I mean that.....
Dennis, you asked some other questions but I'm too tired to wonder back through this thread to find them...sorry.....
I'll get back soon...cause I want to get this cooked round thing straightened out forever, so you centerfire folks will understand it, then we will never have to bring it up again...then I can get on with the stopped muzzle thread...
You know, today is May 28th, 2008......within a few days, we will all completely understand the reasons for a flipper from a barrel that has set for a minute, or two, then fired.........
Johnstown, 1948....Benchrest born.......May 28th, 2008, after 60 years, the truth about this issue is about to see the light of day.....
Your friend, Bill Calfee
Friend Dennis:
I had about 50 things to do today....40 of them is done....10 to go....man, I'd give anything if I wasn't so lazy.......but, I've been like this all my life so it's hard to change.......
Dennis, back some posts ago, man, I hate these big old nasty threads, you asked some questions........one was something like, how quick does condensate form in the bore after a round has been fired...
You ever bring a rifle inside, during winter, that was left in the trunk of you car.........as soon as you enter the heated house, that shinny, polished barrel turns frost gray.....with condensate.....
This is an extreme example, but, the exact same thing happens after we fire one round through our barrel.....as soon as the bullet exits the muzzle, condensate starts forming.......
My friends, I started this thread to discuss how to determine if we have our muzzle stopped.....man, I simply can't believe that the centerfire benchrest community doesn't understand the "cooked round" problem....I'm sorry, no disrespect intended....I mean that.....
Dennis, you asked some other questions but I'm too tired to wonder back through this thread to find them...sorry.....
I'll get back soon...cause I want to get this cooked round thing straightened out forever, so you centerfire folks will understand it, then we will never have to bring it up again...then I can get on with the stopped muzzle thread...
You know, today is May 28th, 2008......within a few days, we will all completely understand the reasons for a flipper from a barrel that has set for a minute, or two, then fired.........
Johnstown, 1948....Benchrest born.......May 28th, 2008, after 60 years, the truth about this issue is about to see the light of day.....
Your friend, Bill Calfee
D
Dennis Sorensen
Guest
Bill, if you click on the "Quote" button rather than the "Post Reply" button, the text will be in the box as above so you don't get tired looking for it...
That is what I have done with my post to show you how it's done...(as above)
The same questions are still there...
I don't think anyone is saying water in the bore is not a problem....
...but would not the big difference in pressure and velocity also contribute to a flyer?
Does your test include firing a "cooked" round through a just fired barrel that has no water in the bore? ... and have that "cooked" round that has higher velocity and pressure that will cause stiff bolt lift go "in" the group of "uncooked" loads? Can you rule out the big velocity and pressure difference as any cause of inaccuracy?
3 more simple questions easy to answer...
How many seconds does it take for water in the bore to build up with a closed bolt? ... with an open bolt? How hot does the barrel need to be to have this happen?
.
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M
Mike Marcelli
Guest
Actually, when I was in highschool, this girl used to call me Bill, so I told the guys that was the name of my privates. She'd walk by and say "Hi, Bill" and all the guys would snicker. Oh to be young again.
B
BUSHMASTER1
Guest
I might would have believed the answer until the above post. I'm no scientist, but it would seem to me that once the barrel is above ambient temperature, it would not attract moisture until cooled to almost ambient temp. again. A cold barrel into hot moisture rich environment I can buy. But not the other way around.
B
BUSHMASTER1
Guest
Man ya'll type fast I mean the post of Bill's above.
jackie schmidt
New member
Mike
At least she didn't say "little Bill".........jackie
At least she didn't say "little Bill".
........jackie
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M
Mike Marcelli
Guest
Jim:
If you'd like, I have a neck tension meter I could loan you to investigate your theory. It's interesting how much even the thin necks can vary over a very few firings, but I digress.
I've not ascribed to the idea that there is water vapor in the barrel of a smokeless powder rifle -- except for that found in ambient conditions and as a byproduct of combustion of course (NOx, COx and H20 are the byproducts elluded to above) . Steel does indeed adsorb water. But, for all intents and purposes, it is a steady state unless you heat the barrel to a static temperature of around 300 degrees F. Then, the barrel will not adsorb water, but it will desorb it. As far as I know, no one is heating a BR barrel to a static temperature of 300 degrees F, so adsorption/desorption is not an issue -- especially given the amount of water that is produced during a firing event).
If, as has been postulated, water is a lubricant in a barrel, I'd expect it to act as all barrel lubricants act (be it oil, graphite, BN, MoS2, WS2). It would lower the pressure and the resulting area under the P vs. time curve, and show a lower measured velocity than would an unlubricated barrel.
Of course, this is not what we see when we "cook" a round. Rather, we see the result of adding heat energy to a combustable system, namely that it burns faster and hotter. The faster burning powder results in a higher peak pressure and larger area under the P v. time curve and ultimately a higher measured velocity.
For those of you having a difficult time pictuing this, imagine lighting a piece of paper on fire with a match. Now, light the same piece of paper on fire with a torch. The paper lit with the match starts to burn slowly, but the paper exposed to the torch bursts into flames. Why? Because the torch supplied more heat energy to the paper than the match. Smokeless powder is paper plus an accellerant. The more heat energy you supply to it (either through a hotter primer, rounds sitting in the sun, or in a hot chamber) the faster it will burn. In a closed system, the faster burning results in higher pressures and higher measured velocities.
I'm still not sure what condensation forming on a cold barrel has to do with any of this. I've never seen condensation form on a hot barrel and I thought that was what we were talking about. If the inside of the barrel is hotter than the ambient temperature, you are not going to form condensate inside the barrel. That's not how things work. Sorry. Water is more soluble in hot air rather than cold. When you expose hot air to a cold surface, the air holding the moisture cools and water falls from solution. When you expose water to hot air, it evaporates.
Gotta go. Clients calling to rib me about "Bill Marcelli."
G
GLF
Guest
just some tought..........
1) the mith of the "stopped muzzle"
how is possible, in ours phisic world to stop something that vibrate at irregular ratio due internal friction? - internal friction affected by gilding material of the jackets, velocity of the round, crude and packed layout of carbon, jacket material, substances used in powder ecc -
2) the mith of water or condensated air moisture.
in my short lesson of aerodinamics, i've always listen that the moisture waves forms up and away from a flyng object, not in front, but maybe i'm wrong and if i apologize myself to not have payed attenction at those lessons, btw those days are away.. IMO in rimfire world could happen, and it happen but isn't the air the responsible of that , but the wax that melt under the wave pressure caused from the bullet starting down in barrel, that heat it and disgregate in minor particoles , most opf them, are h2O.
3) the mith of cooked round:
true and real not mith but reality
4) rimfire are not centralfire.... sound stupid?
yep but is a fact not an opinion.
what work there is not true that could work here and the opposite, but somthing that work here could work there and the opposite.
on tuning..... i've my personal anecdote: just returned at home from the SS, reading log data and look at the targets, i've found that my rifle was in tune all the days, i change nothing, i've not suffered a 1/4 bullet of vertical in all the week, but some horizontal...... 30mph of wind gust misreaded caused sometimes......
i've see vertical only in three targets, but wasn't tune gone, but first shoot high... ( stupid things than happens if u recognize the problem, think to hold but late.. havin' just fired the second shoot ... just to confirm the theorie.. stupid man..)
GLF and i quit
1) the mith of the "stopped muzzle"
how is possible, in ours phisic world to stop something that vibrate at irregular ratio due internal friction? - internal friction affected by gilding material of the jackets, velocity of the round, crude and packed layout of carbon, jacket material, substances used in powder ecc -
2) the mith of water or condensated air moisture.
in my short lesson of aerodinamics, i've always listen that the moisture waves forms up and away from a flyng object, not in front, but maybe i'm wrong and if i apologize myself to not have payed attenction at those lessons, btw those days are away..
IMO in rimfire world could happen, and it happen but isn't the air the responsible of that , but the wax that melt under the wave pressure caused from the bullet starting down in barrel, that heat it and disgregate in minor particoles , most opf them, are h2O.3) the mith of cooked round:
true and real not mith but reality
4) rimfire are not centralfire.... sound stupid?
yep but is a fact not an opinion.
what work there is not true that could work here and the opposite, but somthing that work here could work there and the opposite.
on tuning..... i've my personal anecdote: just returned at home from the SS, reading log data and look at the targets, i've found that my rifle was in tune all the days, i change nothing, i've not suffered a 1/4 bullet of vertical in all the week, but some horizontal...... 30mph of wind gust misreaded caused sometimes.....
.i've see vertical only in three targets, but wasn't tune gone, but first shoot high... ( stupid things than happens if u recognize the problem, think to hold but late.. havin' just fired the second shoot ... just to confirm the theorie.. stupid man..)
GLF and i quit