Dimpled balls again

[coloradoclyde]

I think she was referring to sprue removal, but still sounds like a good idea.

 

[matt denison]

I poached this from your link:


"A lot of people think a ball without dimples will fly further. Conversely its kind of like a knuckleball, it really doesn't know where it's going, it's predominantly driven by drag force."

Always remember that a golf ball is spinning with reverse English. The dimples create a buffer of air around the ball as it spins and reduces drag so it holds velocity longer and thus flies farther. A round ball from a smoothbored gun doesn't spin - or shouldn't spin. Conversely if it is dimpled between two rasps it will present an uneven surface forward which I think intuitively will actually create more drag than a smooth surface. Air planes are smooth...

 

[coloradoclyde]

Actually....planes are not smooth.
The aerodynamics of drag and parasitic drag are far more complicated.

Are you a pilot?

 

[coloradoclyde]

http://www.grc.nasa.gov/WWW/K-12/airplane/dragsphere.html

let me know if you still have questions.

 

[tree]

In NSSA competition at 25 and 50 yds I have shot both smooth
And dimpled balls out of repro M 1842 .69 smooth bores.
For me the dimpled balls yielded slightly better scores
When shooting at standard black targets. The balls are
Covered in Lee liquid and loaded on the powder.

 

[Leatherbark]

I read that article yesterday. The 48 grain charge precludes us from using it for hunting so I was no longer interested. I guess for competition it would be alright.

It seems I read the theory is that the fire all around the ball as it is going down the tube is centering it. I get decent accuracy using a cushion wad over and under the undersized ball with low powder charges, but still use a patch and 110 grains of 2f to get the most accuracy out of my 20 gauge Carolina but I feel it is just a matter of time before I crack that thin wrist on this smoothbore.

 

[BrownBear]

It's sure easy to demo that something is at work. My son-in-law got curious and used silicone to smooth over the dimples on half a golf ball. When he whacked that thing it cut a great big curve like none you've ever seen, then fluttered around like a knuckle ball as it slowed down.

Makes me think if I was to dimple a lead ball by any means, I'd want it REAL uniformly dimpled.

 

[matt denison]

Dimpled airplanes?

I've seen lots of airplanes, they all looked pretty smooth to me. The rivets are set "just so" so that they are flush with the surface. Airplanes have steering wheels and so don't need to be accurate, drag on an airplane is inefficient, takes more power and more fuel to fly 'em through the air. I think they spend a lot of time and brain power trying to make them as aerodynamic as possible.

OTOH, we choose to shoot these round balls, dimpled or not. If you want really slippery bullets that are really accurate then elongate them, put a point on the front and you'll have something with real ballistic coefficient. It will go really straight for a long ways if you spin it.

I am not a pilot.

 

[matt denison]

Forgot to mention, I do get Muzzleblasts mag. I did read the article. I did anticipate this coming. I also thought the auther was being a bit tongue-in-cheek. That is the nicest thing I can think of to say about the whole article. I hope he had fun writing it, maybe even got paid to write it. Good for him.

Some people are such poor shots that any variation has to help. He owned that gun for how long? (25 years) before he put a front sight on it. Then it was a miricle that he finally shot a good group. Then the group he shot with the smooth balls at that short distance is all over the paper, Can you blame that on the smooth balls? Really...?

 

[coloradoclyde]

Well!....I am a pilot and I have bucked more than one rivet and they are anything but "flush"
A plane needs some (specific) drag in order to fly,
Even if you managed to get a plane to fly without drag you wouldn't be able to control it.
Ever shoot an arrow without fletching?

 

[matt denison]

I forgot, are we talking about dimpled balls or dimpled airplanes? Seems to me that anything that flys through the atmosphere has some drag on some level, not argueing that. In fact I'm not argueing at all. Just an old man trying to have a little fun with this subject. :surrender:

Happy New Year Clyde!

 

[George]

Just an old man trying to have a little fun with this subject. :surrender:

Happy New Year Clyde!

It's always a fun subject, with the good shooters highly skeptical and the other fellows hoping it's the magic they are always looking for. :haha: :blah:

Happy New Year, everyone.

Spence

 

[coloradoclyde]

I wasn't trying to start an argument either.
I tried rasping balls and it did improve my accuracy but not enough to warrant the P.I.T.A of rasping so I abandoned it for the K.I.S.S. approach. :grin: :surrender:

Happy new year to you also! :thumbsup:

 

[nhmoose]

I remember Ken Bresien at Fort TY laughing about "rifling" a smooth bore with 180 grit being good for 2 dozen shots for record and NO One could tell.

He was a great barrel maker and fantastic shot. When the controversy of in-lines became an issue he showed up with an 1870 rifle with center hammer making it an inline. Damn he was a rabble rouser.

I was a signer on the target he shot breaking Horace Warner record with the same gun Horace hade made. This was in the 1990's at the old Fort TY ML *** range at Fort Ticonderoga NY

 

[dcriner]

My understanding is that dimples on a golf ball trip the aerodynamic boundary layer, causing the ball to travel with turbulent air flow around it (instead of laminar). The transition between laminar and turbulent flow is governed by the Reynold's number (Google it). With a smooth golf ball, the flow can switch between laminar and turbulent, causing the ball to fly erratically.

A bullet's muzzle velocity is high enough that the flow will, I think, always be turbulent. In other words either a smooth or dimpled round-ball bullet will fly straight, but a smooth bullet will have less drag and travel farther.

 

[coloradoclyde]

Correct! velocity is a factor but a large round ball fired from a muzzleloader quickly becomes subsonic....if it ever was supersonic to begin with.

 

[ord sgt]

After reading the story in MB, I went to work on some .678 cast roundball. Went to the range today with my 1777 Charleville.After filing down the casting sprue, I took a rasp and rolled the balls on my work bench with the rasp.
Off the bench, the target was out at 30 yards. 70 gr FFg. A group (?) over a 6 inch area developed in the 7 oclock area of the target. Raised the barrel and started started hitting in the black.

Cold and windy conditions limited trigger time but the roughed up roundballs showed promise.

 

[crockett]

Well, if you have the article (I throw my old issues out), it's my recall that the dimples improved the accuracy- at least for the Bevel Bros. If I recall the improvement was only slight. I thought the Bevel Bros said that's why they dimple golf balls (I'm not a golfer).
The other issue was how "dimpled" the dimpling needs to be to get any improvement- or as others have said- just depends on the gun or shooter.
If the competitive shooters at the NMLRA events don't bother- that says a lot.

 

[Grandpa Ron]

Being an incessant diddler and a bit of a sponge for any new idea, I have heard the pros and cons of many ideas. They include:
Ӣ Breaking the sound barrier destabilizes the ball.
Ӣ Light load so that the ball never breaks the s ound barrier between gun and target.
Ӣ Heavy load so that the ball never drops below the sound barrier from gun to target.
Ӣ Dimples do not work above the speed of sound.
Ӣ Dimples are good because the ball will drop below the speed of sound.
Ӣ The blow by centers a ball.
Ӣ Wadding cradles the ball acting like a tail fin for a short distance.

The MB article also said one of the shooter dipped their lead balls in alox another bee wax. Now there is something I had not thought of. :hmm:

Over time I reasoned that, out of a possible score of 100, the load gets you to the 80-85 the remaining 15 % is shooter. The shooter is a variable that cannot be predicted.

Still, I love the chase.

 

[Col. Batguano]

Doesn't the underspin on a golf ball imparted as it leaves the angled club increase the air pressure on the underside (while decreasing it on the top), which helps keep it planing upwards (or aloft longer), and increasing the distance of the shot? Same thing with a hook or a slice (my specialty).