Where does the energy go?

[paulvallandigham]

I have to always remember that all mass has gravity. Even humans attract electrons from atoms and molecules around us. That is why microscopic dust particles make me sneeze in the dry weather.

The lead balls, flying down range, also have "gravity" and attract electrons. But,the air that hugs the surface of the balls will act as a " lubricant" if you will allow, so that the air rushing past the ball, actually does not touch the ball. The spinning ball actually attracts more electrons from nearby atoms, because its mass has a bit more gravity, than the NON-spinning ball. Our Planet, and our moon are approximately the same distance from the sun, yet the two bodies have radically different amounts of gravity. One spins on its axis, as well as spins around the sun, while the other does not spin on an axis, but rides along with the planet as it orbits the sun. The moon is obviously smaller, but part of its lesser gravity is due to the fact that it doesn't spin on its own axis. Even more interesting is the fact that the Earth's core actually rotates in the opposite direction that it spins on its axis.
I used to talk about these things with a college roommate, who is a physicist, now. Even he admitted that scientist have "theories" on how these things work, and affect objects in movement, but they really only come close with their calculations. There always seems to be the need for some "fudge factor".

I am convinced that discussions about rifled vs. smoothbore fall into that category of concepts that require a fudge factor for both balls to actually act the same. We know they don't act the same in flight, but can't get a handle on all the reasons they don't. :surrender: :hmm:

 

[Larry Pletcher]

. . . .The spinning ball actually attracts more electrons from nearby atoms, because its mass has a bit more gravity, than the NON-spinning ball. Our Planet, and our moon are approximately the same distance from the sun, yet the two bodies have radically different amounts of gravity. One spins on its axis, as well as spins around the sun, while the other does not spin on an axis, but rides along with the planet as it orbits the sun. The moon is obviously smaller, but part of its lesser gravity is due to the fact that it doesn't spin on its own axis. . . .

Paul,
This is getting way off topic, but I need to say 2 things. The moon does indeed rotate. It rotates once in the same time it completes 1 revolution. The rotation and revolution are completed in 27 days, 7 hours, and 43 minutes.

Gravity does not depend on rotation. An object's gravity is determined by its mass. The pull it exerts on other objects depends on its mass and the distance between them. I'm siding with Newton on this one.

Getting back to the smoothbore and the rifled barrel, my gut says the difference in this theoretical problem is a matter of internal rather than external ballistics.

Regards,
Pletch

 

[longcruise]

We are trying to come up with an answer to an erroneus question. IOW, we are trying to explain an effect that has not been shown to exist. The quality of answers we arrive at are directly related to the quality of the questions we ask.

 

[TKelly]

With the same mass and same velocity they will fly the same distance before hitting the ground assuming the ball fired from the smoothbore travels in a straight direction like the ball from the rifled gun will do.

Yes Zonie, the same mass, absolutely! The same muzzle velocity, I'm not so certain...

The round ball from the smoothbore will be under less built-up pressure. It therefore, should have a smaller muzzle velocity. This should provide less energy for any type of motion whether it be translational, rotational, or yawing. The round ball from the rifled bore would have been under greater pressure build-up and subsequently, have greater translational energy. This translational energy is used to propel the round ball at a greater muzzle velocity. It's this greater muzzle velocity that provides the greater range for the rifled round ball.
It therefore, traverses a greater horizontal distance.

The only possible reason the ball fired from a smoothbore might hit the ground sooner than the one fired from a rifled barrel is due to deflection from the straight path that the spinning ball fired from a rifle would have.

The extreme case of yawing is always a distinct possibility!

As a ball fired from a smoothbore is not spinning it acts like a "knuckle ball" in baseball and the slightest variation of the surface of the ball will cause it to depart from a straight line of flight due to the various air pressures acting on the forward side.

As already stated, yawing is always a distinct possibility, due to the Magnus effect.

 

[robtattoo]

Blame it on Obama? :idunno:

 

[paulvallandigham]

You are right. :thumbsup: I should have written, It doesn't appear to rotate on its axis in relation to the Earth.

 

[kelleyjk]

Blame it on Obama? :idunno:

that'd be my guess, or maybe global warming...
:haha:

anyway Im curious how many here have ever hit a baseball, lots of baseballs (or fastpitch softballs) and Im not talking about your company picnic underhand toss but real pitching at least over 60mph

spin does effect the flight path granted there are seams involved on these objects that enhance the effect but even a perfectly smooth sphere spinning will fly different from one not spinning (c'mon guys why do you think they started rifling barrels for round balls in the first place so they dont yaw :shake: )? no so they fly in a predictable repeatable manner

that being said, if anything the verticle plane of rotation has more effect on windage than elevation, to prove this shoot some .308 tracer rounds and watch them drift or curve if you will, even the miniscule .223 curves not because of gyroscopic physics but because its "screwing" or swimming through our fairly dense atmosphere

I think the OP's original question couldve been misconstrued I know what hes asking about and probably why. when you "read" historical accounts of "maximum effective ranges" some of what we get is hearsay by uninitiated literary people that take what they heard and inadvertanly rephrase or quote what they heard or thought they heard with no experience or understanding of ballistics

all else being equal MV (ie. chrono speed at muzzle) this would be an interesting demonstration and one that could be performed pretty easy by someone here with a 58 rifle and a 58 smooth bore and a chronograph because when it comes down to it we dont care about powder charges or breech pressure or internal bore friction or anything else before it leaves the muzzle

eg.

- one ball spinning at 1700fps MV
- identical ball not spinning at 1700fps MV

ps. we need spotters, markers, pics and chrono readings to verify all this too if you would let me know when youre done that'd be great :wink:

 

[TKelly]

Hey there Zonie!

You know, I tend to agree with you.

However, I've always read that smoothbores shot slower projectiles, had shorter ranges, and weren't accurate much beyond 50-60 yards.

Well to me, "shooting slower" means smaller muzzle velocity. "Shorter ranges" means that its trajectory is short lived and travels for small horizontal distances.

The accuracy problem can easily be attributed to the unrifled round ball being deflected at some strange angle to yaw out of the muzzle.

Thus far, everything that you've stated has been stellar with the exception of muzzle velocities being equal. I'm not quite convinced of that yet.

 

[kelleyjk]

Hey there Zonie!

You know, I tend to agree with you.

However, I've always read that smoothbores shot slower projectiles, had shorter ranges, and weren't accurate much beyond 50-60 yards.

Well to me, "shooting slower" means smaller muzzle velocity. "Shorter ranges" means that its trajectory is short lived and travels for small horizontal distances.

The accuracy problem can easily be attributed to the unrifled round ball being deflected at some strange angle to yaw out of the muzzle.

Thus far, everything that you've stated has been stellar with the exception of muzzle velocities being equal. I'm not quite convinced of that yet.

I love ya brother but how in the Heck does a round object "yaw" I mean I never could tell the front from the back of a sphere :shocked2:

ya I love the moon too :v

 

[TKelly]

Hey there Just J!

A round ball yaws in a smoothbore ML, by bouncing around within all that bore space until it gets to the end of the muzzle, where it then takes on its path of trajectory. The more it strays from the imaginary linear axis formed between the barrel and the target, the more it yaws. Rifling theoretically eliminated the yaw in most cases and delivered greater accuracy to muzzleloading.

* I could say, the more it strays from the average parabolic trajectory between the barrel and the target.

 

[JMinnerath]

A round ball bounces around inside a smooth bore? Where did you come up with that one?
The patch, the patch! That's what seals the bore, rifled or smooth, not the lead round ball expanding magically on its back side.
Riling gives spin to the ball causing gyroscope effect which helps the ball maintain a truer trajectory.

 

[TKelly]

I described the yaw effect that way in order to magnify that actual physical event, for the purpose of describing, the "Yaw".

Of course the patch is used to take up space withing the bore in order to initiate gyroscopic stability, but there still remains microscopic clearance that becomes of colossal significance when discussing round balls as potential projectiles, under enormous amounts of pressure.

However, your point is well taken.

Thank you

 

[token tory]

I'd guess that we're confusing apples & oranges here a little.
Path has a separate set of math from energy retention. Based on that I'd guess that wherever the path is of 2 identical balls, with identical initial velocity they have the same energy. It is in a different place, but it hasn't "gone" anywhere it's just been moved laterally.

If there were 2 identical ballistics pendulums ( penduli? :idunno: ) at the same distances, but offset in the path of the different projectiles I'd bet on identical deflection on impact. Based on that I'd say the energy went into heat, deforming the material of the ball & the planet itself when the projectile struck. :v

 

[TKelly]

I'd guess that we're confusing apples & oranges here a little.
Path has a separate set of math from energy retention. Based on that I'd guess that wherever the path is of 2 identical balls, with identical initial velocity they have the same energy. It is in a different place, but it hasn't "gone" anywhere it's just been moved laterally.

That's the whole point of contention here. I don't believe that both round balls have the same initial velocities.

My very premise at this time, is that the muzzle velocity of the rifled round ball has to be greater than the smoothbore round ball in order to account for the greater horizontal distance that it traveled.

 

[JMinnerath]

I don't get why you think a ball leaving a smooth bore has to be slower than a ball leaving a rifled bore.
If everything is the same; barrel length, ID, powder, ball, patch, lube, ramming force, etc; the MV have to be pretty close to the same.

I bet somewhere someone has fired a lot of rounds over a chrono just to test for that information.
No doubt there were military tests done at one time to test the differences between smooth and rifled barrels when muzzle loaders were in use.

 

[TKelly]

I don't get why you think a ball leaving a smooth bore has to be slower than a ball leaving a rifled bore.
If everything is the same; barrel length, ID, powder, ball, patch, lube, ramming force, etc; the MV have to be pretty close to the same.

Now there Jminnerath!

You could very well have a point and I am leaning in that direction, as previously stated.
It's just that, after reading throughout the years about slow-moving smoothbore projectiles, I concluded that they must have a smaller muzzle velocity than the rifled ones.
The truth is that, I have always believed that based upon this information, the prospect of rifled round balls being faster, in addition to being more accurate was great.

 

[Danbo]

Getting back to the smoothbore and the rifled barrel, my gut says the difference in this theoretical problem is a matter of internal rather than external ballistics.

Yep.

Question was asked earlier in this thread about how a round ball could yaw...it is a very salient question. They cannot and do not do so from an aerodynamic perspective. They can veer off course due to variables in the flow field as referenced in comparison to a knuckle ball.

Couple more points that appear to be misunderstood by some of you gents:

1) The purpose of rifling in PRB rifles is not to impart gyroscopic stability in the ball, but rather to evenly distribute the influence of imperfections in the round ball flow field in a predictable fashion and thus eliminate the veering tendency common to smooth bore projectiles. Rotation of balls from smoothbores is random, thus the effects of the magnus force and imperfections are likewise random. Rifled bores cause the spin of which the axis is parallel to the flight path. Even the smooth bore 120mm main gun of the Abrams tank takes advantage of this via slight offsets in the dart fins which cause a slow rotation of the projectile. The result for both the Abrams projectile and the PRB is the same...equal distribution about the axis of motion of those influences stemming from imperfection of form, and the elimination of magnus force influence.

2) Whether the ball is spinning or not has no effect on total drag force (sigma). Boundary layer flow is the same for both scenarios and in any case, parasitic drag is not a significant player in bullet or round ball drag. Induced drag is a huge player and in simplified form can be viewed in cross sectional area and velocity context. More of each means more drag. More mass means greater resistance to the effects of drag.

 

[biliff]

After reading this whole thing, I can only conclude we're arguing about a false premise.

The OP was why does a rifle shoot 250 yards and a smoothbore only 70? When questioned about the smoothbore distance, it was said to be a "typo" but no amplifying info followed. I still haven't seen any information as to the basis for the original post. Without a lot more specific information we're pretty much just spinning our wheels.

 

[Danbo]

Very true. I understand the underlying question the OP poses, but there are several assumptions unsupported. I think Pletch narrowed it down well enough if anyone wants to pursue the issue, but I'm also thinking it is an exercise not unlike counting angels on a pinhead.

Generally speaking, the practical applications of smoothbores v. rifles has been understood since long before the revolutionary war. With all things equal the exterior ballistics comparison of a smoothbore and rifle will yield little if any difference albeit the slow spin of the rifle's ball carries minuscule energy in its own right. Where the balls land, comparatively speaking, might be a different story, but not for reasons of retained energy or velocity.

Dan

 

[hoochiepapa]