Long range barrel for Mags

[Hexis]

fixed pressure propellent

Think on it.

The pressure behind the ball decreases the further the ball travels. The original volume is smalle. However, at the end of the barrel, right before the ball exits the barrell the volume behind the ball is many times what it was when the ball was fired. As the volume increases, the pressure decreases.

You are also ignoring the fact that we are limiting the speed of the paintball. A lot of measures in firearms and other balistics are to speed up the projectile. That leads to better accuracy and more energy on impact (only one of which is applicable to paintball). With paintball we limit the speed at the end of the barrel at all times (in normal play). That's where the brutal laws of physics set in. A projectile fired at the same angle and at the same velocity will go the same distance (ignoring outside influences). While there are outside influences, they will generally act on a group of paintballs in a similar way (a head wind will reduce the range of all of the paintballs fired at 300fps, not just the ones fired out of a 10" or 16" barrel).

[SlartyBartFast]

It has to do with free speech and the free exchange of ideas. I'm pretty sure they have those in Canada.

Wow guy, you're bing a little touchy. If you quote something, expect others to comment on it. That's all i did. Geesh.

If you were "directing others", well I pointed them to the conclusion. That what you quoted was hogwash. Don't like having what you quote pointed out as hogwash, well either don't get your pantiesin a twist and give your position, or only quote things you agree with and are willing to defend.

And you're right. Free speech exists. But, you have to face the concequences of what you say. You're free to say it and I'm free to rebut (within the limits imposed on us by the forum owners).

I could be WAY wrong here... but I know in real guns barrel length increases distance and velocity.

As others have pointed out. You ARE way wrong. Longer barrels on firearms increase projectile velocity. And because of the increased velocity, the projectile travels further. But even then the increase is not always significant. The Walther P22 for example is sold as "more accurate" in the competition version because "of its longer sight picture". In other words just because the longer gun is easier to sight down.

As in paintball the velocity at the muzzle is the same regardless of the barrel length, a 6" longer barrel increases distance 6". Nothing more. And for accuracy, look at vortex shedding and the weight and shape of our projectiles. All are factors over which barrel length has no influence.

[Lohman446]

The reason a long barreled firearm shoots further (generally) is because the projectile is going faster at the end of the barrel than a short barreled firearm.

As long as you are adjusting velocity at the end of the barrel (as in paintball), the length of the barrel does not matter.

[Solisman]

I'm tired, so what I am about to say might just be crazy...who knows.

If i remember correctly, after 6 - 8" of none ported barrel, the expansion of the air inside the barrel behind the ball becomes less and less effective. After a certain length (11"?) the friction from the barrel and paintball will actually begin to slow the ball down.

Now with firearms, you're firing at MUCH higher than 300fps. Explosion is caused by the expansion of a gas. At higher speeds, I would assume this 6-8" effective expansion to accelerate the projectile would be much larger. I don't know what but I bet it's probably longer than say...a 6" barrel on a pistol.

So for real firearms the longer the barrel, the faster the projectile will exit the tip of the barrel. As for when the length becomes ineffective, I have no idea.

Here's an idea, if you have one of those TINY barrels, you know, with like 3" of solid barrel and 2" of porting, fire the gun at a set velocity. Then switch to a "normal" 10" barrel that has more than 5" of solid barrel but DON'T change velocity on your gun and see if the chrono'd velocity will increase.

[athomas]

A rifle with a longer barrel has a greater distance to accelerate the bullet. It also has a greater distance with which to impart a spin on the bullet, so it is spinning at a greater speed as well. This all increases the distance and accuracy of the gun. A paintball gun can not use rifling due to the limits in the forces that we can apply to the projectile, plus we are limiting the velocity at the end of the barrel. All paintball guns shoot the same velocity.

There are many arguements about low and high pressure guns causing different forces on the ball resulting in deformation. The fact is, due to the mass of the ball and the small amount of resistance to motion as it sits in the breach, it starts moving at the same pressure for all guns. The pressure inside the fining chamber may vary by quite a bit, but as the pressure is delivered to the ball, it moves away from the source. Thus, the pressure behind the ball never reaches the value of the chamber pressure. The same general forces are exerted on the ball no matter what gun it is fired from. One thing that will affect the pressure on the ball is the inside id of the barrel. A smaller id will require a greater pressure to be exerted on the ball before it will move. A difference in length of a paintball barrel can have a big effect on efficiency due to limiting the acceleration distance or creating additional drag, but won't affect the accuracy or range it the velocity is compensated for by measuring and adjusting the value at the end of the barrel.

Since we are limiting velocity so that all guns fire at the same value, and all guns impart the same pressures on the ball, physics says that all guns will shoot the same distance with the same accuracy. We know there are accuracy differences, but most often those differences are caused by mismatched barrels and bad paint and not by the gun or barrel length or design.

[warbeak2099]

Like I said, rifling. More rifling means the CONICAL BULLET (much more aerodynamic than a ball) will have more spin imparted on it. Thus it will go further because of the added momentum.

[SlartyBartFast]

Like I said, rifling. More rifling means the CONICAL BULLET (much more aerodynamic than a ball) will have more spin imparted on it. Thus it will go further because of the added momentum.

1 - Spin DOES NOT make a projectile go further. Spin stabilises the projectile. Only velocity adds momentum.

2- Bullets don't always more aerodynamic than a ball. But they are capable of being spun to stabilise their fight. But, iven our velocities, the drag IS probably higher for the spere.

http://www.grc.nasa.gov/WWW/K-12/airplane/shaped.html

The drag coefficient for a sphere is given with a range of values because the drag on a sphere is highly dependent on Reynolds number. Flow past a sphere, or cylinder, goes through a number of transitions with velocity. At very low velocity, a stable pair of vortices are formed on the downwind side. As velocity increases, the vortices become unstable and are alternately shed downstream. As velocity is increased even more, the boundary layer transitions to chaotic turbulent flow with vortices of many different scales being shed in a turbulent wake from the body. Each of these flow regimes produce a different amount of drag on the sphere. Comparing the flat plate and the prism, and the sphere and the bullet, we see that the downstream shape can be modified to reduce drag.

[Lohman446]

1 - Spin DOES NOT make a projectile go further. Spin stabilises the projectile. Only velocity adds momentum.

I question the accuracy of that statement on a conically shaped projectile. The aerodynamics of a spinning conical projectile are going to be better than a tumbling one. Probably doesn't make a difference on a sphere. I guess it depends, this thread bounces back and forth between firearms and paintballs so much I am not sure which you mean by projectiles.

[SlartyBartFast]

I question the accuracy of that statement on a conically shaped projectile. The aerodynamics of a spinning conical projectile are going to be better than a tumbling one. Probably doesn't make a difference on a sphere. I guess it depends, this thread bounces back and forth between firearms and paintballs so much I am not sure which you mean by projectiles.

Caught picking nits...

Yes, the spin will affect aerodynamics. But MORE spin after a given RPM wouldn't IMO. Would need to look that up.

But that's not MOMENTUM.

[Lohman446]

Caught picking nits...

Yes, the spin will affect aerodynamics. But MORE spin after a given RPM wouldn't IMO. Would need to look that up.

But that's not MOMENTUM.

Wasn't trying to pick you apart, it was an honest statement expressed with my usual non-certainty. Just trying to make certain that we were all thinking the same thing.

I think to simplify this, at least what I think are the points we agree on

Rifling imparting spin influences firearms due to the nature of the projectile that may affect range and accuracy.

In paintball it does not matter, because not barrel in current production (or past) has been shown to impart spin outside of the barrel. Testing (spinning the entire marker at high RPM, including the paintball within) indicates that controlled spin (not backspin as demonstrated by the flatline / Apex) cannot be imparted to the ball outside of the barrel.

So why rifling works (or doesn't) to increase range is meaningless to the conversation of paintball

[Joshtruction]

I question the accuracy of that statement on a conically shaped projectile. The aerodynamics of a spinning conical projectile are going to be better than a tumbling one. Probably doesn't make a difference on a sphere. I guess it depends, this thread bounces back and forth between firearms and paintballs so much I am not sure which you mean by projectiles.

most bullets do not "tumble" (black powder balls, bucksot etc does) they shoot straight like a dart. Said it before and I'll say it again, Rifling only helps accuracy.

[Lohman446]

most bullets do not "tumble" (black powder balls, bucksot etc does) they shoot straight like a dart. Said it before and I'll say it again, Rifling only helps accuracy.

Without spin to stabilize it what keeps it from tumbling? I'm not buying saying it as being proof.

[SlartyBartFast]

So why rifling works (or doesn't) to increase range is meaningless to the conversation of paintball

Now wait for someone to still bring up the comparison of paintball and rifled BB barrels...

[Sir_Brass]

I still roll my eyes when anyone trys to tell me that rifled barrels increase range or that longer barrels increase range in pball. The reason I own an HH kit isn't b/c I think it increases range, but b/c it DOES increase ball accuracy (I'm serious when I say that my HH kit is pure crack.....it's that awesome.....but it only increases accuracy, never range).

Some think that it increases range b/c you may have shots that will not curve as soon and shoot straight for a longer distance, though the distance it travels is the same regardless. It just SEEMS to fly farther.

[Lohman446]

I still roll my eyes when anyone trys to tell me that rifled barrels increase range or that longer barrels increase range in pball. The reason I own an HH kit isn't b/c I think it increases range, but b/c it DOES increase ball accuracy (I'm serious when I say that my HH kit is pure crack.....it's that awesome.....but it only increases accuracy, never range).

Some think that it increases range b/c you may have shots that will not curve as soon and shoot straight for a longer distance, though the distance it travels is the same regardless. It just SEEMS to fly farther.

But that surely is not due to spin.