What happened to bullets that missed in Aerial Battles?

[pbehn]

From wiki "The laws which govern projectile designs are not well-defined. Certain formulae are used which give the thickness of the shell walls for a known chamber pressure in the gun, and for a particular stress on the shell material. The exact proportions of the shell depend, however, greatly on experimental knowledge." Rotation of ammunition

 

[MIflyer]

One of the odder aspects of warship design is that they are designed to fight ships equipped with the same guns they have.

The reason for this is that if the shells are coming at a level attitude, the way a rifle shoots at a target on the 100 yard range, they will be coming so fast that no reasonable amount of armor would stop them. If the shells are at the limit of their range and are coming down close to vertical then they will penetrate the deck, which is at best lightly armored. The USS Arizona was destroyed by a single finned version of a battleship round descending vertically, dropped by a Kate, and which penetrated the deck and the forward magazine.

So, anything other than having the shells descending at a slight angle is pointless to consider. And by assuming that the incoming fire is the same as that produced by the guns of the ship, that automatically assures that the armor is maximum protection over the ranges where the ship's guns are at their maximum effectiveness.. That same approach was used in prewar aircraft carriers, who were designed as if they were going be attacked by the same cruisers that would be their escorts.

 

[pbehn]

One of the odder aspects of warship design is that they are designed to fight ships equipped with the same guns they have.

The reason for this is that if the shells are coming at a level attitude, the way a rifle shoots at a target on the 100 yard range, they will be coming so fast that no reasonable amount of armor would stop them. If the shells are at the limit of their range and are coming down close to vertical then they will penetrate the deck, which is at best lightly armored. The USS Arizona was destroyed by a single finned version of a battleship round descending vertically, dropped by a Kate, and which penetrated the deck and the forward magazine.

So, anything other than having the shells descending at a slight angle is pointless to consider. And by assuming that the incoming fire is the same as that produced by the guns of the ship, that automatically assures that the armor is maximum protection over the ranges where the ship's guns are at their maximum effectiveness.. That same approach was used in prewar aircraft carriers, who were designed as if they were going be attacked by the same cruisers that would be their escorts.

Maybe there was sound logic in that. Having just read this 15-inch (38.1 cm) Mark I - NavWeaps The longest range hit by battleships was at around 26,000 yards. One of the ships that did it was HMS Warspite, at these ranges her guns were at 30 degrees which was maximum elevation. The time of flight was over a minute. Experiments to increase range mainly involved higher powered "super charges" at 20 degrees elevation. If you want substantially more range at elevations of 45 degrees or more the time of flight is huge and involves including the earths curvature in calculations.

 

[MIflyer]

Yes, I can see that; it's like ballistic missiles. My team launched a satellite for the USN back in the mid-80's that was designed to refine the model of the Earth to increase the accuracy of Trident missiles. And with those large naval rifles they loaded a certain number of bags of powder, depending on the range and type of shell loaded. More range meant more powder and that in turn had to increase the dispersion and decrease the accuracy.

When they reactivated the USS NJ in the 80's they found that the 16 in gun accuracy was poor. It seems that the powder on hand had aged, so they added a chemist to the crew to enable sampling of the powder and refinement of the calculations based on the results. Accuracy then improved greatly..

 

[pbehn]

Yes, I can see that; it's like ballistic missiles. May team launched a satellite for the USN back in the mid-80's that was designed to refine the model of the Earth to increase the accuracy of Trident missiles. And with those large naval rifles they loaded a certain number of bags of powder, depending on the range and type of shell loaded. More range meant more powder and that in turn had to increase the dispersion and decrease the accuracy.

When they reactivated the USS NJ in the 80's they found that the 16 in gun accuracy was poor. It seems that the powder on hand had aged, so they added a chemist to the crew to enable sampling of the powder and refinement of the calculations based on the results. Accuracy then improved greatly..

With all the vagaries of the subject, like the massive differences a small increment in traverse and elevation and different performance of shells and propellants at such ranges I am surprised anything ever got even close. At 30 MPH you cover half a mile while the shell is in the air. To me it is like trying to develop a wedge that puts a golf ball in the hole without touching the green. AFAK the guns themselves changed every time they were fired.

 

[MIflyer]

I understand that during the VN War a FAC calling for an airstrike to hit some NVA trucks in the DMZ was answered by the the USS NJ.

"Where are the trucks?" asked the BB.

"In Sector So and So." replied the FAC

"No," replied the BB. "Exactly where?"

The FAC replied that trucks were going down such and such road and making a Left turn at another road.

"Got it! Clear the area!" responded the BB.

The FAC watched the first round hit just behind the last truck and the rounds walked up the road, got to the intersection, and walked down that road. The people on board the trucks jumped out when the first round hit and ran like hell. They obviously had seen that before.
.

 

[ThomasP]

Hey pbehn,

Seeing as I am an AR type, I just though that I should point out the reference article you cite in your post#61 is based on a publication from 1911 by Chisolm.

A lot has changed since then. As an example, in 1911 Kinetic Energy was not understand by the vast majority(any?) of the weapon designers (only the most hardcore scientists had a reasonable grasp of KE) and most of their calculations were based on the old Momentum based concepts. This led to a large number of formulas, coefficients, and and fudge factors that allowed the relatively inaccurate prediction of the designs, leading to a lot of required experimental testing to get it right. Modern gun & projectile designers have a wide range of knowledge and tools not available back then, eliminating most of the 'tribal lore' based trial by error (and guesswork) that was common in the pre-1950s era. In the early-1900s it was still thought that Momentum was responsible for the projectile's ability to penetrate armour, and hence the equations used in the pre-1950s era had similar wide ranges of coefficients and approximations/fudge factors built into them. Once KE become understand the prediction and design of guns and projectiles become much more efficient. The reason I reference the 1950s era is that it took that long for the knowledge/understanding of KE to filter down to and become adopted by the majority of the general engineering population.

Although there are still some minor vagaries in the design process of guns and projectiles, unless the designs use new materials (with as yet unknown properties) the design process is relatively easy - usually the only serious problems are encountered in the production and reliability of the systems, or if the designers are trying to push the limits of material and technology. There is still a lot of testing of projectile and gun system in the development process, but it is mostly due to the hugely increased demand for a functional design from the start of production, as opposed to many of the performance disasters that occurred in the 'old' days (ie AP projectiles that broke up on impact, fuzes that did not function, torpedoes that did not work, aircraft that did not achieve a speed at least close to what was predicted, etc).

 

[pbehn]

Hey pbehn,

Seeing as I am an AR type, I just though that I should point out the reference article you cite in your post#61 is based on a publication from 1911 by Chisolm.

A lot has changed since then. As an example, in 1911 Kinetic Energy was not understand by the vast majority(any?) of the weapon designers (only the most hardcore scientists had a reasonable grasp of KE) and most of their calculations were based on the old Momentum based concepts. This led to a large number of formulas, coefficients, and and fudge factors that allowed the relatively inaccurate prediction of the designs, leading to a lot of required experimental testing to get it right. Modern gun & projectile designers have a wide range of knowledge and tools not available back then, eliminating most of the 'tribal lore' based trial by error (and guesswork) that was common in the pre-1950s era. In the early-1900s it was still thought that Momentum was responsible for the projectile's ability to penetrate armour, and hence the equations used in the pre-1950s era had similar wide ranges of coefficients and approximations/fudge factors built into them. Once KE become understand the prediction and design of guns and projectiles become much more efficient. The reason I reference the 1950s era is that it took that long for the knowledge of KE to filter down to and become adopted by the majority of the general engineering population.

Although there are still some minor vagaries in the design process of guns and projectiles, unless the designs use new materials (with as yet unknown properties) the design process is relatively easy - usually the only serious problems are encountered in the production and reliability of the systems, or if the designers are trying to push the limits of material and technology. There is still a lot of testing of projectile and gun system in the development process, but it is mostly due to the hugely increased demand for a functional design from the start of production, as opposed to many of the performance disasters that occurred in the 'old' days (ie AP projectiles that broke up on impact, fuzes that did not function, torpedoes that did not work, aircraft that did not achieve a speed at least close to what was predicted, etc).

So you will be able to explain all these vagaries then? If cross sectional area increases as a square function, and mass increases as a cubic function how does anyone anywhere come up with any general rule about "bullets"? How does a boundary layer affect a bullet? What about the Magnus effect? Here is all sorts of stuff to get AR about.
External ballistics - Wikipedia

 

[ThomasP]

Hey pbehn,

If it matters, I am thoroughly familiar with ballistics (internal, external, and terminal) and have worked in the field to a small degree. However, as per our last discussion of a similar nature, explaining it all would require me to write a ridiculous volume of posts (in effect post a small book on the subject on this forum) including the mathematics (which are not easy to present using the notation format available on this forum) in order to thoroughly teach/explain the subject to anyone not already familiar with the physics and (at least basic) engineering involved, to the point that they would have to admit that projectile and gun design is not magic. And if someone is already familiar with the basics I refer to, they would already know what I am saying is correct. And, there are already modern physics and engineering books (large and small) on the subject.

 

[pbehn]

Hey pbehn,

If it matters, I am thoroughly familiar with ballistics (internal, external, and terminal) and have worked in the field to a small degree. However, as per our last discussion of a similar nature, explaining it all would require me to write a ridiculous volume of posts (in effect post a small book on the subject on this forum) including the mathematics (which are not easy to present using the notation format available on this forum) in order to thoroughly teach/explain the subject to anyone not already familiar with the physics and (at least basic) engineering involved, to the point that they would have to admit that projectile and gun design is not magic. And if someone is already familiar with the basics I refer to, they would already know what I am saying is correct. And, there are already modern physics and engineering books (large and small) on the subject.

You are thoroughly familiar with everything on gods earth, the last time I challenged your inventions you accused me of being mentally ill, on a subject I worked in for 35 years. Go and invent stuff with someone else, you never explained anything, just invented daft comparisons between elements like aluminium and alloys like steel, without quoting any specification, standard or norm. You are starting your bluff process again, find someone else. As far as I am aware you still dont know what yield strength is.

 

[ThomasP]

I say once again: pbehn, please grow up.

 

[pbehn]

DerAdlerIstGelandet

 

[DerAdlerIstGelandet]

I see it is getting heated in here. Everyone please relax and calm down. Please keep all debate in a civil manner. The discussion is on the radar.

 

[GrauGeist]

A lot has changed since then. As an example, in 1911 Kinetic Energy was not understand by the vast majority(any?) of the weapon designers

Mauser used the formula Energy = (1/2)mv^2 in the ammunition designed for their K98 (1898) rifle - velocity over mass.

So...it seems to me they knew about such things before 1911 or 1950 or whenever.

 

[ThomasP]

Hey GrauGeist,

Was the formula in Mauser's 1898 version of their design manuals/documents? If so then they may have had one or more of the "hardcore scientists" I mentioned above working for them/providing them information.

The reason I ask is because a friend of mine has been collecting literature concerning gun design and manufacture of all sorts for the last ~55 years, from many countries and companies, including company documents detailing the methodology of both their design and manufacture processes. I am sure he would be interested if he could find an original source copy/facsimile of something mentioning KE from that time period.

 

[GrauGeist]

Then there is a good chance your friend has the docs, as Mauser is a well documented weapon pioneer.

 

[ThomasP]

Possibly, but he and I have discussed this type of thing quite often and he has read/perused all of them at one time or another, and he has mentioned the lack of the use of KE in the the older mathematics of pre-1900s.

I do not know if this will help explain what I am trying to say, but the term Kinetic Energy as we use it today did not exist until the mid-1800s, and it was not fully understand/accepted (even by a lot of scientists) as to how it could/should be applied to things, like guns and projectiles, until the early 1900s (Part of this was due to resistance to the idea by the 'Old Guard' of scientists). It took a long time (the number I have heard from college professors is from 80-90 years) for it to be accepted by everyone to be correct. And the dissemination/teaching of to and adoption by the colleges/high schools and engineers lagged behind another 20-40 years.

 

[GrauGeist]

I find it odd that some think kinetic energy is a new technology.
The theory of kinetic energy is the basis of armor-piercing shell design and this reaches to the late 19th century (which falls into Mauser's ammunition design shift).
Again, the foundation is velocity over mass.

And to add to that, the French were using flechettes in WWI, which is a form of kinetic energy bombardment.

 

[ThomasP]

I would have found it odd (I think) also, but I was lucky enough to have a couple of teachers in High School and College that thought we should have the background on the stuff we were learning, as well as the current usage and understanding. So I got the whole story from pre BC Greece to present day history. Newton thought of Momentum as a form of energy for example, but he knew that there was something off with his math because the movement of an object did not stop when it was supposed to based on this, so he made up a bunch of coefficients that helped approximate the effects of KE. Copernicus and others from the renaissance got close sometimes but did not figure out the Work and KE relationship. gradually over time the formulas for figuring ballistics of a projectile became more and more complex with a larger and larger list of coefficients. The people developing these formulas usually started from a previous attempt and tried to refine it to be more complete and accurate, and some started with a clean slate, none of them realizing that they were gradually creating a formula that more closely approximated the effects of KE in the various phenomenon. It was not until the guys studying Heat energy as applied to gases in the late 1700s that a theory of Work as it applies to raising the temperature of a gas began to develop. This led to the theory of Work and KE as 2 aspects of the same phenomenon. When this idea started to spread the application of the Heat-Work theory became more common and eventually others noticed a pattern and it was applied to the mechanics of larger particles (ie projectiles). It took a long time for all this to happen.

When Einstein published his theories on Relativity, there was some serious resistance due to the fact that his theories relegated Momentum to an undefined 'mechanical' phenomenon, being applied more as a coefficient. For some reason, even today, there is resistance in some quarters to the idea of KE as the energy responsible for movement and penetration.

An example of this is the idea that arrows penetrate things based on Momentum. The idea was last made famous back in the 1950s&60s by a guy with a PhD who bow hunted. Mind you, his PhD was in dentistry, but once his theory was out there it took hold. There are relatively simple classroom level tests/experiments that can be performed to prove that Momentum is not the responsible factor for penetration - the math does not work out. But the math for KE doing Work does.

 

[GrauGeist]

And the longer you brew coffee, the stronger it's flavor.