A CONUNDRUM

[Dr5x]

A CONUNDRUM
Is a puzzle that no easy think is going to solve.
Just about everybody including me considers the steel of our rifle barrels to be SOLID. It's all steel and there is nothing that can get into it, penetrate it because there would be no space or spaces for this penetrating substance to occupy.Everybody happy with that?
OK. Now on page 79 of The Book there is a picture of an iron molecule enlarged 50 thousand times and while it is not steel like our gun barrels you can see it is quite roomy and although steel is a combination of iron and some other elements it is easy to assume, always dangerous, that there still might be room for some additional item like OIL.
We're still mot convinced, Steel, by golly is steel.
Ok , so Charley short starts a nicely fitted patched ball about 6 or 7 inches down the barrel and instead of seating the patched ball all the way down to rest on the powder he turns to a friend and tells him a few lies about the girl who shot him down last Saturday night.
Then he gets into position, aims and fires and of course misses the target but creates a wide spot in the bore. This can represent quite a bit of steel having disappeared. Well there should be a widening of the barrel on the outside if the steel can't be compressed.
But there is no sign on the outside at all.
Here is the conundrum.
Where did that missing steel go?

A pause of an hour or so.
If you have given up my guess, and it is still a guess, is that the molecules of missing steel have to been crushed into the steel molecules circling the wide spot.
I would like to hear alternative guesses.
If you come to believe my guess about all that room in and around the steel molecules just might be right and then several other of my beliefs might be true. as well.
Black powder residue, cursive as acid can have been blown into and among the steel molecules. So too could water molecules causing rust in there as well. A frequent wetting those molecules with a penetrating oil of some variety will fill all those spaces with something that won't attack the steel itself and which will no longer offer spaces for the water and erosive residue to dwell there and cause damage.
Has the conundrum been solved? No. but it has been guessed at with some idea of being right.
It all comes back to"Where did that missing steel go?

 

[Ontario47]

If the bore is bulged the barrel is either wider or longer or both. A long time ago I read an article of a metallurgical study and photomicrographs of polished cross-sections of a antique rifle barrel. The magnified pictures showed cracks from the bottom corners of the rifling almost halfway through the thickness of the barrel wall. The article attributed the cracks to a combination of stress and corrosion over a long period of time.

 

[Dr5x]

If the bore is bulged the barrel is either wider or longer or both. A long time ago I read an article of a metallurgical study and photomicrographs of polished cross-sections of a antique rifle barrel. The magnified pictures showed cracks from the bottom corners of the rifling almost halfway through the thickness of the barrel wall. The article attributed the cracks to a combination of stress and corrosion over a long period of time.

I'm inclined disagree.. On the rifle i had with a bulge the outside measurements were unchanged.
Dutch

 

[bang]

I had a 45cal barrel that was shot a bunch over 40 years. It finally, at its end, developed a loose spot about 8 inches in that was only noticeable when ramming. No outside evidence at all.

 

[William O.]

I think there will always be outside evidence of a bulge and that it would be shown by carefully measuring all the flats with a micrometer. The entire length of the barrel would have to be mic'ed but there would be a change. The use of a straight edge might reveal the change as well. Black powder simply doesn't have the energy to compress steel. However, it might be able to push over the lands into the grooves, resulting in a loose spot that doesn't show up on the outside of the barrel. My .02 cents at least.

 

[Grenadier1758]

I've given that problem some thought since I visited on Saturday. The answer is actually explained by atomic and molecular physics.

While there is the felt bulge where the ball was short started, there is actually only a small amount of steel displaced. As that metal is displaced throughout the barrel walls, the measurement will be small enough that it can't be easy observed. It have required measurements before and afterwards to actually see the displacement.

While in an atom, there is a lot of empty space, that space is controlled by the physics of the structure such that other molecules are too large to enter that space. Water or oil molecules can't penetrate that atomic space.

 

[Vaino]

I've given that problem some thought since I visited on Saturday. The answer is actually explained by atomic and molecular physics.

While there is the felt bulge where the ball was short started, there is actually only a small amount of steel displaced. As that metal is displaced throughout the barrel walls, the measurement will be small enough that it can't be easy observed. It have required measurements before and afterwards to actually see the displacement.

I don't agree w/ your premise. I'm presently 88 yrs old and have had 3 bulged bbls….2 MlLers and 1 CF and all 3 showed the bulge on the exterior of the bbl when miked and the bulge was quite evident.....it was in .001s and the largest bulge was on the CF because of higher pressure and measured .004 even though this bbl had molybdenum steel. The MLers had bulges that miked .002. and w/ both the cause was mud in the bbl as was the CF. My 2 young sons accounted for all the bulges because they were in a hurry as young people are wont to do.

All the bulges were first detected when running a patch down the bore......Fred

While in an atom, there is a lot of empty space, that space is controlled by the physics of the structure such that other molecules are too large to enter that space. Water or oil molecules can't penetrate that atomic space.

 

[Grenadier1758]

I don't agree w/ your premise. I'm presently 88 yrs old and have had 3 bulged bbls….2 MlLers and 1 CF and all 3 showed the bulge on the exterior of the bbl when miked and the bulge was quite evident.....it was in .001s and the largest bulge was on the CF because of higher pressure and measured .004 even though this bbl had molybdenum steel. The MLers had bulges that miked .002. and w/ both the cause was mud in the bbl as was the CF. My 2 young sons accounted for all the bulges because they were in a hurry as young people are wont to do.

All the bulges were first detected when running a patch down the bore......Fred

I think that we are basically in agreement. I said or implied that it would take a micrometer to detect the bulge. The bulge is easily detected with the patch. Because the expansion is spread throughout a thick barrel, it will take a micrometer to detect the bulge on the outside on the flats. A bulge of 0.002" will be difficult to detect by hand even if the bulge is evident using a tight patch.

 

[Dr5x]

I've given that problem some thought since I visited on Saturday. The answer is actually explained by atomic and molecular physics.

While there is the felt bulge where the ball was short started, there is actually only a small amount of steel displaced. As that metal is displaced throughout the barrel walls, the measurement will be small enough that it can't be easy observed. It have required measurements before and afterwards to actually see the displacement.

While in an atom, there is a lot of empty space, that space is controlled by the physics of the structure such that other molecules are too large to enter that space. Water or oil molecules can't penetrate that atomic space.

Then how does rusturoughly cleaned barrel with a n oil coat put on top of the "impenetrable" steel/
Grenadier, we are going around and around on this one until one of us dies and the survivor can claim triumph. As I'm next in line I should give up now but I won't till after the celebration.
Send me an email. so I can update your book.
Dutch

 

[bang]

IMO if one could duplicate exact cause. One with a 1/4" wall and one with a 1/2" wall of same density you would see that the effect on the external surfaces of the 1/4" wall would be more prominent given the stress progression would tend to diminish more in the thicker wall. Makes me believe that the overall measurement difference will be less on the exterior to the interior given the diminishing of the stress per wall thickness.

 

[mushka]

Sometimes discussions like this one give me a head ache. Discussions like this and where is the end of the universe tend to unhinge my thought processes. I am a very pedestrian fellow when molecular or spacial science is the subject. Too small minded I guess. I do like to shoot muzzle loading rifles as they are very simple.

 

[sportster73hp]

Up to this point everyone thinks the steel was moved. I suspect with no bulge measurable that the steel was removed. As we all know the gasses produced when firing bp are “hot” . When the ball is seated , as the powder is burned it pushes the ball out. With room to build pressure the gasses may cut the steel away an also push the ball at a different rate thus missing the target

 

[Dr5x]

IMO if one could duplicate exact cause. One with a 1/4" wall and one with a 1/2" wall of same density you would see that the effect on the external surfaces of the 1/4" wall would be more prominent given the stress progression would tend to diminish more in the thicker wall. Makes me believe that the overall measurement difference will be less on the exterior to the interior given the diminishing of the stress per wall thickness.

YOU KNOW HOW A SHINEY BARREL LOOKS WHEN YOU LOOK DOWN ONE SIDE OR ANOTHER? A VERY SMOOTH EVEN LINE WITH NO BUMPS OR HUMPS. THIS SENECA BARREL WAS AS SMOOTH AS BEFORE. THERE WAS NO DEVIATION WHATEVER.
YOU GUYS ARE TRYING TO HANG ME ON THIS. BUT I CONTEND THAT THERE IS SPACE AMONG THE MOLECULES AND YOU GOOD PEOPLE CLAIM THERE ISN'T.
I FOTGRT THE NAME OF THE ITALIAN GUN MAKER THAT FOR YEARS MADE ALL ITS GUNS OUT OF THE STEEL HORSE SHOES OF THE CARRIAGE HORSES THAT POUNDED THEM ENDLESSLY ON THE STONES OF THE TOWN STREETS TO CRUSH THE STEEL'S INGREDIENTS TOGETHER FOR BETTER, MORE SOLID STEEL.
ALL THE YEARS OF READING AND I NEVER THOUGHT TO MAKE NOTES.
DUTCH