Could the cocker shoot farther?!

[Magluvr]

Does anyone know what type of barrel setup that was?

PF or SF (if so H/L or H/R) or CF

I noticed that the ball was rotating slightly off-canter to the sides. (I think this is what caused the ball to drift off the centerline.) Indicating that the detent was on the on the left hand side of the marker. Meanwhile, there appears to be no "up and down" spin. Interesting!!!!

So, the detent -since I have no other idea of what would cause the ball to spin that way-...
Do you think that the induced spin is consistent? If so then there should be no accuracy problems because ALL the balls would travel along the same path.
If it isn't consistent, then is there any conceivable way to remove the induced spin, (except for removing the detent)?


P.S. I was thinking about it and am guessing that the marker is centerfeed with the detent on the left side of the marker.

[Cristobal]

Magluvur: The ball is moving in flight not because its spinning on account of a detent or other frictional force it encountered in the breech/barrel. Rather its moving like a knuckleball because paintballs are simply bad projectiles. The phenomena is called vortex shedding, and it is discussed in detail in one of the spin physics threads.

The z-body needs a very loose barrel if it is to work well, if at all. Any ordinary barrel induces too much friction and effectively negates any spin the ball picks up in the breach. (See Tom's tech tips.) I find it highly doubtful that a detent could impart enough spin on a paintball to cause a noticable effect on its flight -- especially one which would excceed the random motion caused by vortex shedding.

[Magluvr]

Cristobal-

Correct me if I'm wrong, but... From my understanding vortex shedding would cause the ball to drift, or jerk in any direction. I don't think that it would cause the object to spin. And that the paintball is spinning on a vertical axis is clearly seen in the pictures.

.....Hold the phone!!!!!......

Um, I was checking the pictures again and was wondering are the balls in the picture the same ball, or are they each their own discrete ball?

If they are discrete than everything I have said in this post and previous is cannot be validated by the photo. So, before I bother continuing could anyone clarify the picture.

P.S. If the picture is of discrete balls then is there any place I can find a picture of the same ball in flight. Because, discrete balls won't show spin of any kind.

[Cristobal]

Originally posted by Magluvr
Cristobal-

Correct me if I'm wrong, but... From my understanding vortex shedding would cause the ball to drift, or jerk in any direction. I don't think that it would cause the object to spin. And that the paintball is spinning on a vertical axis is clearly seen in the pictures.

Yes, my understanding is that they are all the same ball -- as I recall, Tom said they used a timed strobe to illuminate them in flight.

I don't know whether vortex shedding would induce spin on paintballs not. As best I undertand paintball fight, my contention is that the slight lateral motion of the ball in the bottom picture is more likely due to vortex shedding than any spin it had coming out of the barrel.

[SlartyBartFast]

Originally posted by Magluvr
Slarty-
Could you explain this thing about the taller guns, would seem to have a flatter trajectory. I don't understand how a taller bodied gun could appear to have a flatter trajectory, merely because their taller.

If the top of the body is higher than the top of the barrel, people tend to sight down the top of the body to the end of the barrel. The barrel is then obviously tilted upwards (but not necessarily obvious to the shooter). When shot the ball goes further. Not because of elves or any inherrent majic in the marker but because the gun was tilted ever so slightly.

Sighting along the top or side of a marker like the Mag, the gun tends to be much more horizontal.

[Miscue]

Not Deep Blue material, moving.

[nerobro]

The Z body produces a LOT of backspin. (comparable to the flatline) And a lot of broken balls if you're using it "properly" (that's with the pad down) Most z bodies are used with the backspin element deactivated. (due to ball breakage, and lack of avilablity of large enough bore barrels...)

However, you're right. sometimes, when there's the last ball in the gun, with a non foamie bolt, you MIGHT get some topspin. However, not enough to matter. IIRC, under 6000 rpm ball spin doesn't really matter. Over 6000 rpm is where you see it's effects.

[FallNAngel]

Originally posted by danheneise
in each system, the bolt is fully forward and the ball is AT REST before air is shot out

Technically, they're not. In a closed bolt system, the ball is loaded and then air is released. In an open bolt system, since the bolt and hammer are linked, when the hammer is moving to open the valve, so is the bolt..which means the ball is moving too. The ball may be moving only a fraction of an inch, but it's still moving. On the other hand, it's not rolling enough (if at all) to make a difference, which is why I said technically.

[DirectHitSniper]

well in REAL guns it has been proven that closed bolt IS more accurate. which is why snipers use them etc.

could someone explain that to me?

[FallNAngel]

I'm not quite sure on real guns and why snipers would only use closed bolt... but in either case, paintball isn't real guns. You're trying to get the same accuracy with a small paint filled gelatin ball that you can with a solid pointed piece of metal... it's just not going to happen.

*edit*
I just thought that I may have said this in a harsh awy. I'm not trying to be rude or anything, it's just that paintball isn't the same as real guns. What works in one, won't always work in the other. For the purposes in paintball, just open vs closed bolt doesn't have enough of an effect on the ball to make a difference.

[DirectHitSniper]

hehe I didn't take it as rude

even if the paintball is round and filled with gelatine... its still shot out similar to a real gun.

maye if anyone knew why closed bolt on real guns is more accurate it could make this easier to understand..

[nerobro]

They aren't filled with geletin. They are filled with ethelyne glycol or other non water liquids. The shells are geletin.

And paintballs DO behave as bullets do. Round bullets. Notice that bullets are not round ;-)

Bullets have a LOT more energy behind them. And the forces seen are much higher. think 10,000psi versus 120psi. Guns deform. Paintball guns, do not.

[cockermongol]

I notice a difference in ark between my new BKO and my old cocker. I used cockers for 2 years and then when I just got my BKO I noticed a difference in the way it shoots (yes, chronoed at the same velocity).

[FallNAngel]

Originally posted by DirectHitSniper
even if the paintball is round and filled with gelatine... its still shot out similar to a real gun.

The way that they're shot is *kinda* similiar.. They both get pushed out of a hollow tube..that's about it. The barrels on real guns can have rifling, which does nothing for paintballs. The shape of a paintball (spherical) allows for vortex shedding which the pointed/conical shape of a bullet does not, which can damage the paintballs accuracy. Spin can be put on a bullet, where there is none on a paintball.

[Mindflux]

Originally posted by cockermongol
I notice a difference in ark between my new BKO and my old cocker. I used cockers for 2 years and then when I just got my BKO I noticed a difference in the way it shoots (yes, chronoed at the same velocity).

That's ALL in your head.