Barrel Design Theory

[davidb]

I was just sitting here reading through threads on AO when it just kind of hit me-

Now, we all know that when you shoot a paintball, the ideal situation is to have the ball in contact with the barrel at two points (usually the seams). Contact all the way around will decrease efficiency and be too sensitive to imperfections in the barrel and paint. One contact point is obviously a problem, as evidenced by the "zebra stripes" seen in testing from paint bouncing back and forth in the barrel.

With today's ultra-round tourney paints, the chances of having either one or the other of the aforementioned problems is increased, despite the constant outcry for perfectly round paintballs (better than egg-shaped, sure, but those seams really were good for something!). When you have seams, you have two points that can be touching the barrel diameter at all times. With seamless, very round paint, you either have the whole thing touching, or one point touching (in theory, if both are VERY round, which is often the case now with some of the nicer paints out there).

Now, obviously, perfectly round paint is replete with advantages of its own, and I certainly don't see companies deliberately and openly going away from the "perfect paintball" course. But todays barrels are designed for imperfect paint, not the perfect spheres that we are starting to see nowadays.

Now, the idea - since paint is never going to be purposefully made out of round, we have to change the barrel. And barrels could be changed to accomplish that ideal situation of two (well, three in this case) points of contact. The idea is this: simply make the barrel so it is not perfectly round! I know it sounds a little off, but think about it- Design the barrel so that at three points along its inside diameter, the barrel wall sticks out ever so slightly more than the rest of the barrel. I'm afraid I'm not able to make an illustration of what this would look like, but I think you'll get the idea.

With this design, every ball would be in contact with the same three points, theoretically making each shot more like the one before it.

When I first started writing this it kind of occured to me, "oh wait - gas efficiency". But, after giving it some thought, it seems that having the three slightly recessed areas, which air could potentially escape through, would not have as much of a negative effect on your efficiency as having the entire ball touching the barrel would. It might even cause an increase in efficiency.

Again, this idea was concieved with ultra-round tourney paints in mind. Whether or not it would work with lower-grade paint, probably depends on just how bad it is.

Just an idea that struck me five minutes ago and evolved during its transition into typed form. Thought I would throw it out there to see what was wrong with it, basically.

[nerobro]

A good paint-barrel match is somewhat dependant on bad paint ;-) the better the paint, the more precice your match needs to be. At least if you want to get the two perfect paths in the talcum powder.

I too dont' see paint mfg's getting away from doing as close to perfect paint as they can.

Have you considdered an oval interior to the barrel? soemthing to garuntee two sides of the ball touches the side?

I'm not sure how effective this would be.. becuase ideally the ball will settle on it's smallest diameer... and then no rotate from there.

I dunno weather we're best off with trying to make barrels that'll encourage a misfit ball to shoot straight. Or just getting barrels to match the paint that day.

[davidb]

It took me a few times of reading through your post to get what you were trying to say, and I'm still not quite sure what you're getting at in the last sentence.

A slightly oval shaped barrel could very well work, as long as the paint was very round. I think the one with the three protrusions would be a little more forgiving of imperfect paint, however.

For those who were having trouble picturing it, I attached a hastily thrown together, highly exaggerated illustration.

Basically the only problem I personally can think of with this design is that it would be harder to machine than a simple round barrel.

[nerobro]

Sorry about that. I was at work. I get a little incoherant when talking to idiots (customers.. I work tech support)

Your idea has been done before. I think J&J was making straight riffled barrels for a long time.

Three riffles is the idea I was tossing around myself. it seems to be the best comprimise.. but what worrys me about riffles is that one side of the ball is always going to get more traction. instead of seaking the loweest two points of the ball like in a normal barrel situaion.. a three rail.. or any rail system may well encourage spin. Then again, that probally needs testing.

From what i've seen, to compensate for really cruddy paint.. a really good barrel interior finish does a good job. My OTP is quite paint tolerant, shooting everything from dice on up to tourny paint fairly straight. the best I can attribute this to is the interior finish.

I'm not sure how we'd make a barrel with riffles.... extrusion is always an option, but would be amke it to the sizes we want...

[J]

...And hey, if this doesn't work, it'd make a great gimic. That always works with paintball...

[nerobro]

Yaknow, you have a really good point there. If the idea is PARTIALLY feasable... and makes some logic... yea.. it works

[Person]

A triangle shape inside a barrel. with rounded corners making those 3 contact points larger. not just 3 tiny contact points but 3 decent sized contact points.

[flanders]

this is a sound idea, in some waysif u have a triange shaped one with 3 contact point and th ball spins, u just ripped ur abll to shreds unles su get the inside perfect, each barrel would end up costing a huge amount
it's just not effective way of doing things, good idea but not perfect, perhaps work on 2 points in an oval barel?

[davidb]

Tiny contact points would be preferred, actually. The less contact, the less friction, the less possibility of a spin being put on the ball.

Triangle shape doesn't work because most of the air would be going straight past the ball.

[Person]

I have to say that is incorrect because otherwise the strait riffled barrels would be insanely accurate and efficient accourding to you. Also, i dont mean a REAL triangle but it is sort of a rounded off triangle not with extremely large gaps.

[Lifted047]

The rifled barrels try to put a spin on the ball, and I've had some luck with them, but not too much. I could see a rounded triangle barrel, I'll have to hop on and design it now. It does seem the idea of all the air flowing past the ball is right, because there would either be a perfect fit and exact contact points, or none. I don't know if anyone follows me. It would also seem that the ball would go into a football shape as soon as it is fired and traveling down the barrel due to the triangle shaped barrel. Anyone still follow? I'll think more of this and post later.

[Person]

I said Strait riffled. Not like the armson stealth, poor quality barrels do it like CMI barrels. Its bassically strait lines going down the barrel. And if the barrel was made properly with the triangle shape it wouldnt really be a triangle shape at all.

[athomas]

Originally the "two points of contact" theory was put in place because the paintballs had a seam which was considerably larger than the rest of the paintball. By sqeezing the paintball we exerted uneven pressure around the ball causing erratic acceleration behavior and flight patterns. By having the ball too loose we just bounced the ball down the barrel. The two points of contact allowed us to guide the ball along with a minimal amount of interference on the surface of the ball. Gas escaping on either side of the contact points were approximately equal so the ball acceleration and flight were consistent and as straight as could be. If the ball isn't perfect, it doesn't matter that much because the air still pushes past the noncontact areas of the ball almost equally.

Enter perfectly round balls. The ideal paintball is a round one. A barrel that fits the ball perfectly will have exactly the same pressures on all contact edges of the ball as it accelerates down the barrel. The ball will maintain slight contact on the entire surface of the barrel. The problem with this is that there is no room for error. If any ball is out of round it will have more contact pressure on one side than the other. The first out of round ball that comes out of the barrel will corkscrew like a son of a gun.

A barrel that introduces two or more artificial contact points will help maintain consistency for all balls. Perfectly round balls will work the best, but even balls with a seam will funtion as well as they do now in properly fitted barrel. The secret to "rifled" barrels would be to keep the points of contact small but not sharp. Don't create too much gap area. Too much gap would create turbulance around the ball. Too many points of contact would make the barrel hard to clean.

An ideal barrel would have enough points of contact to properly touch the two highest points of the ball nomatter how it sits in the barrel.

[magnj]

good idea with the triangle contact points. I have seen rifled barrells befor but never shot one. There is one that has twisted rifling to encourage spinning.

[athomas]

Twisted rifling in a paintball barrel doesn't work. You can spin the outer shell of the paintballbut the mass of the paintball (which is the liquid center), will not rotate with the shell. It renders the spinning action a waste of effort.