Length: 10,12,14,16,18?

[Robbo]

Yes there have been some tests but most of the relevant information on this subject is theoretical.
That doesn't mean for one second it is any less valid because the science people base their results on when theorising is pretty well understood and proven.

All they are doing is applying known science to paintball and although there haven't been too many lab tests carried out, there have been enough to confirm the theorists and also in my experience of 18 years in this sport, I have not seen anything that really contradicts what I am about to say.

The optimum length for a barrel in terms of accuracy is as Bulldog suggests about not much over 10 inches, in fact it's probably a bit shorter.

The reason we end up with longer barrels is due to a mixture of bull****, ignorance and aesthetics.

There are reasons for having longer barrels other than accuracy and these have been mentioned already but I'm afraid if you think an 8 foot barrel is gonna be any more accurate than an 8 inch barrel, then you are gonna be disappointed.
The prime determinant in accuracy is the paintball itself; understand this and you begin to understand the relative futility of other considerations such as barrel lengths etc.

And to flesh this out nominally speaking, I would think the accuracy of any paintball shot in lab conditions (no wind) would be something like :-

96% down to the paintball
2% down to the propulsion (valve mech)
2% down to the barrel

These are approximations to give an idea of the relative influences on the accuracy of a paintball and are certainly not meant to be definitive.

 

[khanzo]

one of the reasons that i personally am lead to believe that people think longer barrels are more accurate, is that it is easier to see down the side of the barrel and look exactly were you are aiming, this was the difference that i personally have found between the 14 inch i use, and the 18 inch front my bro has (for a laugh)

but this would make no difference if the marker was placed in a vice and held still, then shot

 

[Robbo]

Originally posted by khanzo
one of the reasons that i personally am lead to believe that people think longer barrels are more accurate, is that it is easier to see down the side of the barrel and look exactly were you are aiming, this was the difference that i personally have found between the 14 inch i use, and the 18 inch front my bro has (for a laugh)

but this would make no difference if the marker was placed in a vice and held still, then shot

On mid to long range shooting, looking down the barrel is pretty useless because you have an arc on the ball - but for short range (snap-shooting) where you can pretty much flat line people then you haven't got much time to aim anyway... in fact, if you are doing the snap correctly, then aiming is the last thing you need to be doing.
The accuracy attained in any snap shot is in the technical operation and set up of the snap and certainly not within the realm of traditional aiming.

Jamie Abbott on Nexus used to train snap shooting for hours whilst blindfolded and be extremely accurate which pretty much puts the 'aiming' of a marker into its proper context when considering snap-shooting.

 

[khanzo]

i agree with you there that there isnt time to aim when snap shooting and other techniques. But when playing in the woods ect i think that people find it easier to aim and 'place' the ball with a longer barrel, thus leading to peoples opinions that longer barrels are more accurate, which isnt true, they find them easier to aim. Thats what i think anyways

 

[dr.strangelove]

I use a 14 inch, I find it to be a really good all-around barrel length. Without boring you with the 10-20 page articles written on the subject by WARPIG and, uh, some other company whose name I can't remember, the bottomline is this: You need 6-8 inches to accelerate and guide a paintball, and a few inches of porting to distribute gas evenly behind the ball. Using a barrel between 12 and 16 inches, you will find no noticeable difference in "accuracy". Anything longer than 18 inches, and you will actually find a noticeable decrease in accuracy, as the ball will encounter more friction, and too much porting will cause you to lose too much gas behind the ball so it will leave the end of the barrel with less velocity. So take your pick of whatever length you think looks or feels right on your gun anywhere between 8 and 16 inches and you should be just fine.

 

[Robbo]

Originally posted by dr.strangelove
IAnything longer than 18 inches, and you will actually find a noticeable decrease in accuracy, as the ball will encounter more friction, and too much porting will cause you to lose too much gas behind the ball so it will leave the end of the barrel with less velocity. So take your pick of whatever length you think looks or feels right on your gun anywhere between 8 and 16 inches and you should be just fine.

Not so sure that's true Doc, all it does mean is you need more energy (compressed air) to get the job done.
If you go up to a chrono with an 20 inch barrel, you are still gonna set it up for 295 as you would have done for 12 inch barrel.

Since both markers are shooting at 295, albeit with one marker using more air to attain that velocity, this doesn't mean that is going to be any less accurate because it is using more air.

That's my understanding anyway.

 

[dr.strangelove]

Originally posted by Robbo
Not so sure that's true Doc, all it does mean is you need more energy (compressed air) to get the job done.
If you go up to a chrono with an 20 inch barrel, you are still gonna set it up for 295 as you would have done for 12 inch barrel.

Since both markers are shooting at 295, albeit with one marker using more air to attain that velocity, this doesn't mean that is going to be any less accurate because it is using more air.

That's my understanding anyway.

Correct. What I mean is, with all things being equal (same gun, same pressure, same dwell, etc,.), you will notice a decrease in "accuracy" with a barrel longer than 18" than with one say, 16" or shorter. Since you have more friction to overcome, and more gas escaping behind the ball, you need a higher volume of air and/or higher pressure to propel the ball to the same velocity, as you say. The result is horrible efficiency, obviously, but it also affects the flight path of the ball by not releasing it from the barrel until after it's optimum speed has been achieved (it doesn't start flying until it's already started slowing down, so you're not getting optimum speed and range). The bottomline though, for the original poster, is: anything longer than 16" is overkill, and will decrease efficiency and "accuracy", generally speaking, and there should be no difference between barrels from 10"-16", all things being equal.

 

[Robbo]

Originally posted by dr.strangelove
Correct. What I mean is, with all things being equal (same gun, same pressure, same dwell, etc,.), you will notice a decrease in "accuracy" with a barrel longer than 18" than with one say, 16" or shorter. Since you have more friction to overcome, and more gas escaping behind the ball, you need a higher volume of air and/or higher pressure to propel the ball to the same velocity, as you say. The result is horrible efficiency, obviously, but it also affects the flight path of the ball by not releasing it from the barrel until after it's optimum speed has been achieved (it doesn't start flying until it's already started slowing down, so you're not getting optimum speed and range). The bottomline though, for the original poster, is: anything longer than 16" is overkill, and will decrease efficiency and "accuracy", generally speaking, and there should be no difference between barrels from 10"-16", all things being equal.

Doc, this is a hole that quite a few people fall into when trying to understand Paintball ballistics.
There is no evidence that I have seen that supports this idea, theoretical or otherwise and please remember here, we are talking about significant effect.
The fact you have more friction to overcome just means you need more energy to overcome that friction if you wish to get the same velocity as from a shorter barrel.
I’m afraid it’s a fallacy mate to introduce the notion of more friction means less accurate.
The ball starts to slow down after the first 6 inches and so all paintballs measured in normal length barrels are already in the slow-down phase and the length of the barrel just determines how far into that phase you are when you chrono.

You must remember basic physics here mate, and if that ball comes out the end of that barrel at 295, whether it comes from an 8 foot barrel or an 8 inch barrel, the trajectory is gonna be pretty much the same all other things being equal.

And the trajectory of a paintball has two basic components that we must consider as ballers, length and accuracy and trust me Doc, they are gonna be pretty much the same (in fact exactly the same if ALL other considerations were equal) from both length barrels.
A few years back I spent some time in the test lab of Tom Kaye who was the owner and designer of the Automag and he had conducted some tests and I saw all the data he had collected.
He had high speed camera pics of differing barrels under different conditions and he made a pretty comprehensive assault on trying to understand paintball ballistics.
I was lucky enough to spend more than a few hours with him in his lab and at his house where we discussed the subject for a fair few days.
I wasn’t really surprised by any of his findings other than what he had discovered about spin and turbulence with most paintball talk on the subject being bullsh!t but it’s hardly surprising there was so much ignorance about when there had been no real serious assault on the subject.

Peace.

 

[John C]

Wow Robbo you are so lucky to have that opportunity with Tom Kaye.

I think an important part of paintball disappeared he left the sport.
What are we left with? Spiral porting and seal forward technology




Anyway back on topic one of the biggest mistakes people make is comparing paintball guns with real guns.

In terms of ballistics, our paintguns have more in common with 'welly throwing' than they do a rifle.

 

[Robbo]

Originally posted by John C
Wow Robbo you are so lucky to have that opportunity with Tom Kaye.

Trust me John, I have been very lucky in paintball, very lucky indeed.
I have met and become friends with an awful lot of real cool people ..... and I have made a few enemies along the way but that's generally because I try to tell the truth