Time to lay this to rest....

[tb-303]

its really a question of distance. a rifle is better at longer distances therefore more accurate at a distance.if it wasn't there would be no rifles just pistols(yep there are loads of variables to take in to account but back to basics its true) but the kind of distances you would fire pellets in a paintball game you don't gain much if anything with a inch or two here and there on the barrel. i was looking at the bigger picture rather than just paintball markers. what will effect it is if the barrel has rifeling inside(grooves inside the barrel to set the pellet in a spin) a friend has a rifelled barrel but i ain't tried it yet. again in real guns this does make a difference.

i might be opening a can of worms here, but why do you say a paintball marker is completely different to a real gun? they are both are designed to fire a projectile(again doesn't matter what pellet,bullet or shot) through a barrel and to hit a target.(ie a gun). ignore the firing mech.weither its air,gas or a charge.they all cause an expansion of gasses to cause pressure in the gun to set the pellet in motion.so what is it i'm missing?
tb(don't hurt me)-303
this isn't a "having a go" at anyone reply.i'm learning here too. and i'm interested in what you guys know that i don't.

 

[Beaker]

A longer barrel in itself wont make the paintball fly straighter but your personal accuracy can be affected - it all depends on how you aim your marker.

If you (like many people) use the tip of the barrel then it's simple trig.

If you have an 8" barrel then then angle from your eye to the tip of your barrel will be greater than an 18" barrel.

Let's see if this works - imagine you are looking it from above

eye
I
I
I_ _ _ _ - tip of 8" barrel

eye
I
I
I_ _ _ _ _ _ _ _ _ _ _ - tip of 18" barrel



as you can see the longer barrel means much shallower angle between your eye and the tip of the barrel - therefore it is a LOT easier for you brain to work out where it's supposed to point the marker.

It's not necessarily just to do with the barrel itself making the paint more accurate but what allows you to aim the marker the best.

 

[Manning26]

Here's the facts from Airgun Designs, who actually do tests on this sort of thing, instead of sitting around theorizing like us.
In theory spinning a projectile on the axis of flight adds gyroscopic stability as well as averages out any imperfections in the surface air flow. Paintballs leave a bad turbulence wake behind them that "walks around" the back of the ball as it flies through the air. This is the main cause of a paintballs inaccuracy as the turbulence tail drags the ball around sideways in flight. Spinning the ball should create a tornado like vortex in the back of the ball thereby evening out all the turbulence so the ball is not pulled any particular way.

So great you say lets do it and get more accuracy!! Well if it was possible it would already have been done. The problem is the liquid fill, when you rotate the shell, the liquid tends to stay where it is. The best example of this is a glass of water with ice floating in it, when you rotate the glass the ice stays in the same place (you have all seen it). So if you can grab the ball hard enough to go from 0 to about 10,000 RPM's in 5 thousands of a second Yes the shell is spinning but the fill is not. When the ball leaves the barrel the viscosity of the fill slows the shell down but the fill's rotation is speeding up from the shell too, so you get an almost instant reduction of the RPM's out of the barrel. The balls rotation does not come to a complete stop because the shell does impart some spin to the fill.

In order to test this properly we actually developed a gun that spun the barrel, with the ball in it, up to 30,000 RPM's and then shot the ball out. In this way we knew the ball and the fill were completely up to speed when it left the barrel. We had visions of a spinning barrel paintgun that would make that high speed turbo wine! Unfortunately this didn't improve the accuracy because the ball is still too light.

As a final test we developed a barrel that had three razor edged knife blades running down the length of the bore. Using our plastic paintballs they wedged in the blades perfectly and we spun up the barrel and fired more test rounds. Because the knives would cut the ball we could examine them after the fact to see if they were rotating in the barrel etc. Again unfortunately we saw no improvement in accuracy and gave up.

Based on this data we believe round paintballs are too light and have lousy aerodynamics to expect any more accuracy than what we are currently getting. When the military came to us and wanted a more accurate non lethal system we made a bullet shaped, spin stabilized paintball that far outperformed any equal weight round projectile. Accuracy by volume has been, and will remain, the best way to score eliminations.

Just the facts from,

AGD

If that didn't help this thread, I really don't know what could.

 

[crom-dubh]

T-B

The reason why I say that a paintball marker and a rifle are different is because the propellant used in real bullets do not have the same properties as gas used to fire a paintball. The bullets propellant (gunpowder or cordite) need time to burn off, hence the same cartridge fired from a pistol say has less range an power than from say an SMG. The longer barrel gives the propellant more time to burn thus creating more energy to be used by the projectile. In a paintball gun, the gas used does not create more energy if the barrel is longer. But since a paintball needs a certain amount of time to reach terminal velocity, the barrel is just there to stabilize it in flight.
Also with rifling in a barrel, as the paintball is not tight in the barrel there is a little give. This is due to the balls being rather fragile. For rifling to properly work, The ball must hug the barrel tight. When muskets were around the lead balls had to be wrapped in oiled leather when used in the early rifles. They then had to be hammered down the barrel to ensure the tightest fit. Anyone wanna do that with a paintball?

 

[Manning26]

Yes, sometimes.

 

[tb-303]

crom and manning
guess i should pay attention and really comment on the subject at hand,paintball. as a projectile paint pellets aren't the best by a long shot(no pun intended) so markers do the best job they can and some very well.and for the field a long range marker isn't necessarily needed(no doubt there are exceptions,and i aint messin with that dude on page 34 of the new PGI to find out)especially when most of the time you can't see too far ahead anyway.
the ultimate thing which effects accuracy is the user. yo could have the best and most scientifically proven accurate gun in the world,but if you're high on crack and shakin' like an electrocuted monkey you ain't gonna shoot for toffee.
so try different barrels and see how you get on(which is generally the answer which could be used for any thread in this tech forum,try it and see what you like) then go buy one! and stop listening to us couch scientist wannabies(me anyway)
tb(out gunned)-303

 

[paintballguy]

ahhhh!

An 8 inch barrel doesnt have the same accuracy as an 18 inch barrel. And manning26 I use an 18 inch barrel and have no problems setting up my marker to kick ass with it.

 

[Manning26]

Paintballguy, I totally agree with you, but the optimum barrel length for anything is 12". You're gaining nothing with your 18" except extra trips to the air line. Although, theoretically, your paintballs should hit the ground six inches farther out than someone with a twelve, so that there is something, I suppose. And I'm sure you do kick ass all over the place with it, I'm just saying you'll kick the exact same amount of ass with a 12".

 

[Manning26]

I didn't include this tid-bit, but others have eluded to it, the ball needs so much of the barrel to be unported so it can build up speed, especially low pressure guns (they need more length), we're talkin' 8" for your standard gun, and 10" for low-pressure. If you've got ports inside of those measurements then you've got to turn up your velocity to compensate, which means you're using more air. The remainder of the barrel only adds drag to the ball, and really not much else. The ball is already up to speed, and on its path, so why would you need any more length?

 

[drfrankenstein]

I really do not think that length in this manner will help but as some one said it is what you feel comfortable with. But what I do think is that BALL TO BARREL SIZE DOES MATTER. take the freak system for example (this is what i shoot on my bushy) it has several different sized sleeves to fit. I have yet to see another barrel shoot any better after you get the sizes fit right.

the balls will vary in a batch but the over all consistency will produce exceelent results.

by the way the tip i shoot is 16" hahaha