Canadian Airgun Forum

The other day I was shooting my Recon, and wanted to see which of the pointed pellet's I had in my collection was the most accurate. I noticed one thing, that at shorter distances(10m and under) it really didn't matter if the pellet was smooth or ribbed, they were all equally accurate, but when I started to get a little further out, the smooth skirted pellet's started losing their grouping a little, while the ribbed skirted pellet's began to tighten up a little. This was especially noticeable between H&N Spitzkugeln's and RWS Superpoint Extra's, the difference between Kovohute Diabolo Boxer's and Beeman "1223" Pointed Blue Coat's wasn't as pronounced, but still noticeable. What surprised me was that the most accurate pellet at both short, and long distances was a l/f pellet, the skenco type 4 Black Match, which outshot the type 1's I had it against, the only other lead pellet I tried that was consistant at both distances was the Remington field point's, In my opinion this was the cheapest pellet with the highest quality standards, and exceptional accuracy at both long and short distance,.
The accuracy differences between "smooth", and "ribbed", are probably due to the rib's causing a little turbulence which aided the pellet's spin, much like the difference between a smooth golf ball, and a dimpled one,,Dimples equate to further distance. Cheer's, Andy.

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QB-78-D .22 w/Fitco 4-16x44ATL
QB-57-D .22 w/Fitco 2-7x32k
2x,.XS-B4-2A .177&.22 w/Fitco 3-9x40
XS B9-1 w/AimPoint CompM2
XS B2-2A .22 w/Simmons 3-9x40
TAC1 Extreme w/BSA 3-9x40/Var,. Kit
2240/2289g w/Tasco 2-6AOE
Gamo Recon w/ Fitco 2-7x32K

Those that have done exhaustive testing with many brands and types of pellets have proved that the ribbed pellets and the smooth pellets will perform virtually identically - with no advantage or disadvantage to either style. The most common pellets used by field target shooters are all of the smooth skirt variety, and they shoot accurately out to 55 yards (and beyond). The ribbed skirts are simply aesthetics, nothing more.

Could you be more specific in your definition of the "long distance" at which you found the Skenko type 4 pellets to be the "most accurate"?

The distances I was shooting, short distance was 25ft, and long distance was 50ft. Now, 50ft may not seem like long distance for you, but don't forget I was shooting a Recon, , personally I do think that there is a difference between the two, not much, but still noticeable(to me anyways)Cheer's, Andy.

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QB-78-D .22 w/Fitco 4-16x44ATL
QB-57-D .22 w/Fitco 2-7x32k
2x,.XS-B4-2A .177&.22 w/Fitco 3-9x40
XS B9-1 w/AimPoint CompM2
XS B2-2A .22 w/Simmons 3-9x40
TAC1 Extreme w/BSA 3-9x40/Var,. Kit
2240/2289g w/Tasco 2-6AOE
Gamo Recon w/ Fitco 2-7x32K

Yes, it is very true that every individual rifle or pistol will react differently to one pellet style or another. The reality is that there is no benifit to ribbed vs smooth pellets. The rib was part and parcel of one of the most common forms of pellet manufacturing, which used a rotary die to form the pellet. Today, most pellets are formed by a plug being swaged into a pocket to form the final pellet shape. A lot of faith was placed in the ribs causing drag which would act to keep the pellet flying true, but that is all it was. The heavy head was the reason, along with the spinning imparted to the pellet by the rifling. The ribs didn't add any more stability to pellets shot out of a smoothbore gun vs non-ribbed designs.

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Keyrigger
CAFTA Governor

When you are long winded, is that a sign of Wisdom or Old Age?

In theory, ribs on airgun pellets should break up/smooth out the turbulence caused by a projectile travelling at high velocity through air.
This is the justification for dimples on golf balls.
I am not aware of any definitive research that would prove or disprove the dimple effect on airgun pellets.
I have never seen a non-dimpled golf ball.
In the last three days I eliminated 3 red squirrels, 2 black squirrels and 18 corvidau at my bird feeders.
The distances are 15 to 30 yards.
The guns are scoped BSF S70 and Diana 27.
The pellets are smoth RWS Superpoints and CPLs.
The success rate is 50%.
I get similar success with both smooth and dimpled/ribbed pellets.

I have always wondered about the difference.

I doubt the ribs do much for aiding centrifugal rotation, instead probably adding drag and slowing it down over time.

However, there are things on high end cars and race cars called diffusers which aid in stability at high speeds.

http://www.rsportscars.com/foto/06/sale ... 1_1600.jpg

http://www.elises.co.uk/models/s2/rear.jpg

This may attribute straighter flight.

I think the only way to determine the benefits, or lack there-of, would be to take two dimensionally exact pellets, one with ribs, one without, and compare them.

A different brand of pellet without ribs may have certain advantages over a pellet with them, if it is made by another manufacturer with different physical parameters.

I had actually seen a test that was done to see why Golf Ball's are dimpled. it must of been about 25 yrs ago, the show was a Brit Science show called "Don't Ask Me" w/ Professor Magnus Pike,,and Yes I'm serious, , anyway's Magnus proceed's to test a smooth ball against a dimpled one, He asks the studio audience which ball they believe will travel further, nearly all raised their hand's for the smooth ball, Out comes the golf Pro who proceeds to show that the dimpled ball will alway's travel further than a smooth one, I guess that's why we don't see smooth golf ball's anymore,LOL, I wonder if this could have an effect on Big Bore shooting where they use .45 & .50 caliber lead ball shot. It would sure make for some interesting testing, wouldn't you say?, Cheer's, Andy.

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QB-78-D .22 w/Fitco 4-16x44ATL
QB-57-D .22 w/Fitco 2-7x32k
2x,.XS-B4-2A .177&.22 w/Fitco 3-9x40
XS B9-1 w/AimPoint CompM2
XS B2-2A .22 w/Simmons 3-9x40
TAC1 Extreme w/BSA 3-9x40/Var,. Kit
2240/2289g w/Tasco 2-6AOE
Gamo Recon w/ Fitco 2-7x32K

So what about steel BBs, then? Would dimpling them make a superior projectile? Could this be a million dollar idea? I don't really golf, but when I have tried to whack a ball I am amazed how those things take off to the side, like a knuckleball or something.

As I recall the theory behind the dimples on golf balls, it has to do with imparting spin to the ball, in order to stabilize it's flight. The ball that spins as it flies will tend to be easier to control the trajectory of, and as a side benefit, often tends to travel a bit farther.

Any projectile fired from a rifled bore already has the necessary spin to achieve stability, whether it is a pellet, or a .50 cal. musket ball.

i always thouight that the dimples were there to impart lift, like the wing of an airplane , and i cant remember the exact scientific terminology for lift , something about making the air move faster on the top of the wing or something like that. so igues technicaly if you used round shot like in sirjeigo's 50 cal behemoth that would mean that the round would go farther.

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now shooting a qb79 with a Leapers 4-16x56 AO with a rgb mil-dot ret.

I think lift/spin may have something to do with "Bernoulli's Principle". Problems arise with smaller object moving through the air because of viscosity effects and fluid dynamics. For years scientists couldn't figure out how honey bees could fly. "Aerodynamically impossible" as it was described. Slow motion photography reveals that little insects actually sort of "row" through the air with their tiny little wings.

On a related note, I recall a NASA study a while back looking at surfaces. They studied shark skin because of the efficiencies Mother Nature endowed through a gazillion years of evolution allowing these animals to move through a fluid efficiently. It turns out that shark skin is very coarse, almost pebbley (is this a word?) in nature,rougher than a football, and that as the animal moves through the water the surface produced "micro turbulence" that they surmised acted to provide a type of low friction bearing surface resulting in overall lower energy use by the shark. The idea was to apply this knowlege to airplanes.Never saw much more than that one study.

On a related related note, the Russians developed a 400 MPH torpedo many years back, essentially just a big-ass rocket which vented a lot of combustion gas out of the tip/nose. This enveloped the rocket/torpedo in a shroud of gas, keeping the water away from the torpedo and dramatically reducing drag. "They" say it was one of these torpedoes that inadvertently sank the KURSK.

So anyway, I think I'll try to dimple some BBs and design a good experiment.

The dimples on a golf ball may have something to do with lift.

My Grampa has been golfing probably since it was invented, so I'll ask him.

Airsoft, however, also uses backspin.

It results in a flatter trajectory, possibly to do with lift.

On the airsoft wikipedia, they mention the Bernoulli's Principle as well.



http://en.wikipedia.org/wiki/Hop_up#Hop ... _principle

Googling "dimpled BBs" reveals people have been thinking about this for years. It may not be worthwhile to pursue this idea, dunno. The problems include creating consistent surfaces to maintain consistent trajectories.Maybe exposing the BBs to a corrosive environment for a fixed amount of time, but simple abrasion would probably do. Dimpling may be more appropriate for larger airsoft or paintball ammo.

smooth are more accurate in my guns

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Diana 350,460
HW 77, 97K,30S,
Beeman R1
BSA Superstar Magnum 2
umarex 92fs x2, Sig 225, S&W m&p
crosman 1322

Yes, but is ribbed more pleasurable? =p

Sorry, noone did it, I couldn't resist. XD

Please forgive.