Powdery resi-dew effect on lead air-o-dynamics

[Spot Shooter]

Hey fellers,

I heard afore that a little oxidation on a round ball don't affect it at all?

Don't seem to me that'd be true if it changes the surface texture, which to be more "scientific" would cause a different amount of friction on the balls surface in each spot. This ain't to mention that the ball'd grab the patch differ'nt as it tride ta spin the ball goin' down the barrel.

Just my thoughts, I'm think'n that tak'n balls or conicals thet have varied surface texture hunt'n or shoot'n be a bad thing.

Whatcyall think?

Spot

 

[roundball]

I've shot boxes of old Hornady balls I've bought at gun shows that were white and had powder come off on my fingers...decided to shoot them at the range as they were to see if there was any difference...only tried 50yds but they shot the same as if they were pure clean brand new

 

[GB1]

... I heard afore that a little oxidation on a round ball don't affect it at all?

Don't seem to me that'd be true if it changes the surface texture, which to be more "scientific" would cause a different amount of friction on the balls surface in each spot. This ain't to mention that the ball'd grab the patch differ'nt as it tride ta spin the ball goin' down the barrel. ...

If you were firing a smooth, round sphere (roundball), the air flow would separate soon after going around the middle of the ball. When the airflow separated it would create a vacuum on the backside, slowing the ball. This is like the vacuum you feel when a tractor-semi passes you.

The roughness caused by the oxidation may swirl the air more before it reaches the backside. The air flow next to the bullet, interacting with it, is called the boundary layer. Forgive me for a lack of everyday words, but the swirling would add momentum to the boundary layer. This means that the airflow would follow the contour of the ball's surface better, separating later and making less vacuum on the backside. Less vacuum means less drag and more downrange energy.

Hope this helps.

 

[Claude Mathis]

I heard afore that a little oxidation on a round ball don't affect it at all?

In the laboratory perhaps, but not in everyday shooting.

 

[Stumpkiller]

But what about if we're firing a round ball roughened up by the impressions of the fabric patch and spinning along it's directional axis at thousands of revolutions per minute?

I don't think oxidation would make a measurable difference. :imo:

 

[Claude Mathis]

But what about if we're firing a round ball roughened up by the impressions of the fabric patch and spinning along it's directional axis at thousands of revolutions per minute?

If you give me the relative humidity and the phase of the moon (after all, the Moon's pull on the Earth causes the tides) I'll try to calculate the over effect at 100 yards. Oh, and I'll need the elevation as well. :youcrazy:

 

[GB1]

In the laboratory perhaps, but not in everyday shooting.

Why do you think golfballs have dimples? It's not to pay homage to Shirley Temple, it's for airflow stuff.

 

[Claude Mathis]

Why do you think golfballs have dimples? It's not to pay homage to Shirley Temple, it's for airflow stuff.

OK, I'll bite. Why don't we shoot dimpled balls in our rifles? Would that make them more accurate? :hmm:

The oxidized coating has no more (practical) effect on trajectory than the flat spot left by the sprue. In my opinion (and experience).

 

[GB1]

OK, I'll bite. Why don't we shoot dimpled balls in our rifles? Would that make them more accurate? :hmm:

In a sense, we already do. Lead roundballs may look smooth, but they're not smooth like ball bearings.

The oxidized coating has no more (practical) effect on trajectory than the flat spot left by the sprue. In my opinion (and experience).

I don't doubt that you're right. Other factors outweigh surface irregularities.

 

[Stumpkiller]

Why do you think golfballs have dimples? It's not to pay homage to Shirley Temple, it's for airflow stuff

Ah, but maybe it's just Madison Avenue hype to get you to buy all new "improved" golfballs every season. Ever see a McDonald-Douglas engineer smacking a F-18 all over with a ball-peen hammer to get it to fly faster or a TWA ground crew chief doing the same to a 747 to squeeze out a few more miles on a hundred gallons of fuel?

 

[roundball]

Actually, that is the truth behind the development of golf balls...they even experiment with different "patterns" of dimples with various size dimples mixed in...creates a "boundary layer" cushion of air around the ball giving it increased lift, hence longer ranges.
In the old days, original golf balls were wrapped with a pure smooth covering, and it became apparent as a golf ball was used more and more, it's exterior got rougher and rougher.

As the exterior got rougher and rougher, it also became apparent that the golf balls flew farther and farther the more roughed up the exterior became, which launched the investigation into golf ball surface texture & designs, evolving to what we have today.

I can only assume they don't dimple aircraft fuselages because there's some trade-off point to the whole process but jetliners do use that same boundary layer principle with leading edge slats and trailing edge flaps during takeoffs and landings for increased lift.

Incidently, a somewhat related piece of information you might find interesting:

I bought 5 new boxes of Speer .530's off auction, the seller simply put the 5 plastic boxes into a shoebox size carton without any packaging material, they all split open from rough handling of course, and 500 loose round balls had dimples / dents all over them from days of bumping and banging into each other...literally looked like miniture golf balls but they fired just as accurately as if they were brand new ones.

 

Spotty: Your thoughts are "spot on". PUN ALERT! :crackup: :crackup:
Some people here are talking out thier poopers.
A rough surface on a sphere DOES affect its flight.
A golf ball IS dimpled for aerodynamic reasons as any 1st year engineering student knows. Dimpled golf balls DO fly better than smooth ones and it's not hype.
Will your rough roundballs fly truer than a prfectly smooth one? YES. Without a doubt, provided certain conditions are met. The 'dimpling' should be uniform. Hard to do on a roundball. The roundball should stay BELOW the threshold of the sound barrier. Which they all do after 50 to 75 yards. NOTHING sheds velocity faster than a roundball with the exception of a brick. It's really hard to load a brick in a proper muzzle loader anyway. :what:
If you could properly dimple a roundball uniformly then it would shoot better than a smooth roundball.
Unfortunately the only way to proove this would be to test the theory in a bench vice with a target grade barrel.
In the feild it would be difficult to tell the difference between smooth and dimpled.
I know a guy that dimples his balls. :huh:
I shudder to think of it! :crackup: :crackup: :crackup:
YACKMA ::

 

Yes- if it were possible to 'dimple' the balls properly, they'd be much more accurate in smoothbore muskets. Delivered without a spin, they'd remain unspining and tracel perfectly? No?

 

[canyonman]

You are right it is hard to load a brick, but well worth the trouble, as they will bring down anything from elk to elephant. :winking: Do you use 1 or 1.5 lb bricks for whitetail?

Larry