How about some science: a dimpled slug?

[Hogtamer]

OK, it's high 90's in Ga, lots of time in the recliner....was watching the US OPen last week and wondered....why does a golf ball have dimples? A cursory search and you discover that a dimpled surface has about 1/2 the drag of a smooth surface....hmmm. A round ball leaving a barrel with any kind of spin would create low pressure on the opposite side of the spin, prolly not good. But a Dimpled Lee slug coming out of barrel perfectly would _________? Retain velocity better than smooth? Be more accurate because of more equalized air pressure? Somebody get out the slide rules and pocket rocket Attachment 108349

[Themoose]

Hogtamer,

I'm by no means a rocket science, but the dimples on a golf ball help stabilize it because they are completely covering the surface of the sphere... if they were only on one side, I think the golf ball wouldn't fly nearly as well... You may be better off shooting a round ball that is dimpled than shooting a Lee or Lyman slug with dimples only on the leading edge.

[Hickory]

The dimples reduce the drag on the ball while in flight.
The same as the boattail on a bullet reduces drag.

Drag, is when the air that passes over a surface comes in contact with the object.
The dimples are recessed and therefore have no contact with the air that passes over the surface of the golf ball.

[AggieEE]

I'm going back about 40 yrs to my fluid flow class. A smooth round ball will have laminar air flow over it and the air will "stick" to the back side of the ball causing more drag. From the drawing I remember about 1/2 way around the back side. Turbulent air flow while causing more drag while in contact with the ball seperates from the ball sooner so the net effect is less drag. I don't know how well it would work with the high subsonic, low supersonic speeds we're dealing with. Now that I've been thinking about it IIRC the airflow goes turbulent before we get to a useful round ball velocity. But, try it, the worse thing that will happen is you've found something that doesn't work.

[pipehand]

Y'all are forgetting the Magnuson effect. When a golf ball is hit properly, there is a backspin, and the dimpled top of the ball is retreating relative to the air, and the bottom of the ball.is advancing. This creates a vacuum above the ball and provides lift. That is why a dimpled ball goes further. It is also why a poor hit will hook or slice in a curved manner. If the laminar flow model pertained to boolits then Lover in designs would drop less than a single grease groove bore rider.

[ghh3rd]

That could have been the biggest thing, since powder coating boolits!

[upnorthwis]

I tried dimpling both .40 and .45 cal. several years ago for BPCR. Didn't work for me.

[cpileri]

Well, lets take this from an "innaccuracy mitigation" standpoint:

lets say that a perfectly fired smooth ball from a smoothbore needs no dimples.

But what about an imperfect smoothbore, or one where a slightly undersized ball touches the side of the bore just a bit and does pick up some spin: maybe topspin if it hits the topof the bore, or backspin if it hits the bottom, or other etc (i.e. not rifling style spin); then the dimples might help?

Might be worth a try!

of course, how would we get lots of the correct sized dimples on enough balls to make a decent sample size?

What is the ratio of each golf ball dimple to the total surface area of the golf ball: that might give us a place to start w a .678 RB, but how to get them evenly distributed over the ball is another problem altogether.
C-

C-

[35remington]

No matter what you do to the surface of a roundball or hollowbase slug, the BC will be miserable. Hoping for huge increases in BC with little divots will be a fool's errand. Gold balls don't fly at supersonic speeds, and if this was of great help somebody would and will be doing it already. There's a reason they're not.

[leeggen]

Now hold on here, nobody has given facts as to it not working or even having been tested. I want to see some factual info. on this subject and maybe some already test results from mfg's.
CD

[fastfire]

Someone with a CNC could make a dimpled mold to test the Dboolit..

[Zymurgy50]

Someone with a CNC could make a dimpled mold to test the Dboolit..

Or someone with a lathe and a welder could make a golf ball cannon, fire regular dimpled golf balls and then fire golf ball that have had the dimples filled in with bondo,,,,,,,

[cpileri]

i think a swageing operation is the best idea. get the pre-made ball; then into a 'dimpling die' and swage the dimples in.
Either that, or meticulously use a center punch and make one dimple at a time- NOT!
C-

[fastfire]

Or someone with a lathe and a welder could make a golf ball cannon, fire regular dimpled golf balls and then fire golf ball that have had the dimples filled in with bondo,,,,,,,

I built a golf ball cannon, use oxy-acetylene neutral mixture. need to chrony it cause goes so fast ya can't see the ball.

[Akheloce]

I built a golf ball cannon, use oxy-acetylene neutral mixture. need to chrony it cause goes so fast ya can't see the ball.

Careful, those things bounce off trees something fierce.

When I shoot my cannon with golf balls, it seems they slice pretty easily. The rotation imparted on the ball causes it to go in whatever direction the rotation dictates... Rarely consistent.

I would think that in a firearm, any imperfection on the muzzle crown would be exaggerated by a dimpled projectile, causing serious inaccuracy. Interesting idea though.

[Janoosh]

A dimpled ball has less bearing surface in the bore. Will that equate to more velocity for the same amount of powder? ? The dimples obviously work best at a given speed. Will that apply to firearm velocity???
A patch/ wad will make up for any bore irregularities. ..
Fascinating. .

[Janoosh]

A dimpled ball has less bearing surface in the bore. Will that equate to more velocity for the same amount of powder? ? The dimples obviously work best at a given speed. Will that apply to firearm velocity???A patch/ wad will make up for any bore irregularities. ..Fascinating. .

[longbow]

I made some dimpled balls many years ago just by tumbling by hand. The goal was to smooth off sprues though, not to increase BC.

They looked good and were pretty evenly dimpled. I wound up giving them away though and never shot any myself... DOH!

If you have a drum type tumbler try dumping out the media then drop in a dozen or so balls and tumble for a few minutes and see how they come out. Tumble 'till done then load and shoot. Of course we will want a field report on accuracy and trajectory with graphs and photos with captions.

My suspicion is that the balls will pick up a spin from turbulence, if nothing else, then will take a curved trajectory to somewhere you weren't aiming. But that is wild speculation on my part and we need empirical data so get to it man and don't forget the photos.

Longbow

[littlejack]

A few years back, those boys on Myth Busters done a test. They wanted to see if the dimpled surface had an impact on gas
mileage if transposed to the surface of a vehicle.
They covered the vehicle (car) with an inch or so of clay. They then removed "radiused" amounts of the clay all over the
vehicle to resemble the surface of a golf ball. They then ran a gas mileage test.
Next, they removed the clay from the outside of the vehicle, and put it inside the vehicle. This allowed the weight of the car to
be the same for each test. They then ran the gas mileage test with the car again. IIRC, results were that the car with the
outside "dimpled" surface got better mileage than the car with the "smooth" outside surface.
Just sayin.
Jack

[pipehand]

I had a Honda Fit get dimpled up pretty good in a hailstorm. Didn't notice an improvement in mileage, so I had the dents fixed. Works great on golf balls though.