Barrel Length and Accuracy

[azheat99]

Just an FYI. March APG published an article on barrel length and accuracy. It was done using pretty good scientific controls. Although, I'm am somewhat biased since I wrote it! Hopefully this will settle some of the debate on barrel length.

[painTech]

they are all the same over 4 inches.

[azheat99]

Not quite, but they all may be equal if they're longer than 8. That first part of the barrel is critical to accuracy.

[hitech]

I don't have the article to read, so, how did you define accurate?

Also, have you read the paintball spin physics thread?

[Miscue]

Originally posted by azheat99
Not quite, but they all may be equal if they're longer than 8. That first part of the barrel is critical to accuracy.

Why?

[RRfireblade]

Originally posted by azheat99
Hopefully this will settle some of the debate on barrel length.

Then post the article unless this is just a cheesy attempt to boost Magazine sales.;)

[FreakBaller12]

Q, isn't it because that is the bore size, before muzzle break occours, isn't it the control part of the barrel.
This is why barrel kits have different bor sizes for only the first few inches or so of the barrel.

[SlartyBartFast]

Originally posted by toyotaboy12
This is why barrel kits have different bor sizes for only the first few inches or so of the barrel.

No, they have different bore sizes only for the first part because the first part is interchangeable. THe last part has to be bigger than the biggest insert.

If matching paint is the best thing to do, it would be far more efficient to have 3 or 4 barrels with precision bores for the whole length.

It honestly wouldn't cost that much more than a kit if you just bought 3-4 barrels that were realistically priced and not priced for the gimmick and hype.

[manike]

Originally posted by SlartyBartFast
If matching paint is the best thing to do, it would be far more efficient to have 3 or 4 barrels with precision bores for the whole length.

Or 10 precision barrels at 1 thousandth increments in bore size... just like I bought from Tom ;) ...

Now I just need to find time to put them on the lathe and cut them to fit cocker threads... and maybe with a little nicer outside... :D

[Dayspring]

Show-off! :p


Originally posted by manike


Or 10 precision barrels at 1 thousandth increments in bore size... just like I bought from Tom ;) ...

Now I just need to find time to put them on the lathe and cut them to fit cocker threads... and maybe with a little nicer outside... :D

[GT]

or we can all reslove this issue by agreeing that shooting un-uniform objects is what really throws of accuracy and not the 125 piece of Al.

[Kevmaster]

Originally posted by gtrsi
or we can all reslove this issue by agreeing that shooting un-uniform objects is what really throws of accuracy and not the 125 piece of Al.

by ununiform you mean: sorta-spherical, un-aerodynamic, non-constant-density, non-constant-mass, irregular dimples....

right?

[Miscue]

Originally posted by gtrsi
or we can all reslove this issue by agreeing that shooting un-uniform objects is what really throws of accuracy and not the 125 piece of Al.

Ha, agreed. Everyone would think it was silly if we had "better" tubes to launch eggs with, or sponges. Maybe try to spin the eggs with rifling. A more accurate Nerf ball launcher, perhaps. The problem with these things, including paintballs, is there is NOTHING that you can do to get them to shoot better except for velocity control. Paintballs themselves SUCK for accuracy! But a lot of people do not want to believe this! It is unacceptable!

The ONLY thing a barrel does is act as a pressure chamber that helps accelerate the ball to 300fps. That's it! They all shoot at a straight trajectory when the ball is 1" out the barrel. It's the 100 feet after that, that is the problem. Velocity control is the ONLY issue... and shorter barrels and paint/barrel match happen to improve velocity control.

[shartley]

Originally posted by gtrsi
or we can all reslove this issue by agreeing that shooting un-uniform objects is what really throws of accuracy and not the 125 piece of Al.
shhhhhhhhh ;)

[SlartyBartFast]

Originally posted by Miscue
and shorter barrels and paint/barrel match happen to improve velocity control.

Has anyone actually proved this through testing?

As far as paintball/barrel match, I'd like to see a statistical analysis of a typical batch of paintballs for roundness and sphericity.

Couple that with a study of the effect of the delta between paint size and bore size on velocity consistency. (I guess TK started doing this, at least it would explain all those barrels manike bought.)

Then we'd probably end up proving the statistical stupidity of many of the insert/kit sizes.....

[azheat99]

As far as accuracy is concerned, there is more than one way to measure it. Rather than determining how far a ball hit from a specific point, I measured the diameter of where they impacted. At a reasonable distance, you wouldn't expect a paintball to hit the exact mark you're aiming at like a real bullet. It therefore makes more sense to measure the spread of where they hit knowing this will be lower than the point the barrel is aimed.

I'd like to post the article, but given that APG owns the rights to it, that's not possible. Spend the few bucks or read it at the store.

I also agree that the physics of a paintball also limits its accuracy. But, we have to work with what we're given. This article was'nt to say any barrel or gun is better than another. It was simply a well controlled study on how barrel length affects accuracy. I think most of us knew that a 30 inch barrel would be ridiculous and no more accurate than a standard length barrel. In order to say this with confidence, a little scientific method needs to be applied. I am happy to know that running around with my 10 inch barrel is just as good as using a 15 inch barrel.

So, pick any color,style,material,brand barrel you want. Know that from 10-15 inches they're all equal. I'd like to see a little more research so that there's some proof to the claims some of these manufacturers make. It also seems this may have stimulated a little thought on the subject, which is also good. Thanks!

[punkncat]

Matching bore size has two distinct advantages.
One is that you minimize barrel breaks with a bore size slightly larger than the average size of the balls you are using.
The second being that a bore size very close to the average size of the balls will increase effeciency.

Beyond that accuracy is affected by the quality and consistancy of the paint you are using.

I have found that the best thing in a barrel is either adjustable bore(kits) or the biggest bore you can find(fixed).Nothing messes up accuracy quite like a barrel break.If you eliminate those and chops,like w/ lvl 10, then its as good as it can be.

Oh and SHAME ON U FOR THE PLUG!

The length of the barrel really doesn't play into accuracy IF its firing off a bench or fixed position.This is of course assuming that the barrel is long enough to allow for the ball to travel up to speed consistantly.When being held by a person then the longer the barrel the more opportunity that you will move and throw off the ball as it travels the length of the barrel.
The only advantage I have seen from a super long barrel is the ability to push back an air bunker , or the reduction of sound.

[azheat99]

OK, I'm willing to take the walk of shame.

Yes, this test was done with the gun fixed to a workbench. And yes, there was a difference in accuracy. But this was only seen with the 8 inch barrel (slightly less accurate than all other lengths). As far as I know, this is the only test that has really provided solid evidence on the topic. I hope that other points brought up in the conversation will encourage some others to conduct some decent tests rather than speculating on the topics. If anyone does read the article, please feel free to comment. I may shed a few tears in my beer, but gladly drink the rest!

[hitech]

Originally posted by azheat99
As far as I know, this is the only test that has really provided solid evidence on the topic.

Tom did extensive testing to determine if ANYTHING affected accuracy. Some of the results are posted in deep blue.

[RRfireblade]

Originally posted by azheat99
OK, I'm willing to take the walk of shame.

Yes, this test was done with the gun fixed to a workbench. And yes, there was a difference in accuracy. But this was only seen with the 8 inch barrel (slightly less accurate than all other lengths). As far as I know, this is the only test that has really provided solid evidence on the topic. I hope that other points brought up in the conversation will encourage some others to conduct some decent tests rather than speculating on the topics. If anyone does read the article, please feel free to comment. I may shed a few tears in my beer, but gladly drink the rest!

Just curious since I don't have the article handy,I'm assuming you used one peice barrels,completely unported and a single bore size through out the full length of the barrel(not stepped) and all barrels of the various tested lengths are of the same bore size as well and all testing was done using paint from identical batches and verified to be basically the same overall size and weight?

Correct?

[azheat99]

An 8 and 10 inch one piece barrel was used then a 3 piece with only the center piece changed to adjust barrel length. All barrels used the same bore sizer, which is what contributes to a barrels accuracy. Whether a barrel is stepped or not should not matter since it's the initial part of the barrel that's important (within reason, wouldn't want to go from .689 inches to a 2 inch bore). Porting does not affect accuracy, though it does effect efficiency, requiring more gas to accelerate the ball to the final velocity. Velocity was also kept constant for all shots, 290 +/- 5 fps. Each ball used was sized for the bore used. Balls that fell through or were not easily blown through the bore were not used. Measuring the sphericity and weight of the balls may be another article. I'd be interested in seeing how the different brands compare for these two variables. It was also conducted in an RV garage to avoid the effect of wind. I'll admit the test was not perfect, but did remove variables that we all deal with in normal play such as variable ball size, a moving gun, and wind.