# Help with Paintball (-;

#### shonoflight

For the last month I have been looking for the perfect snipping barrel for shooting a paintball. I have talked to a bunch of guys and they say that the longer the barrel the more accurate it will be but you lose range. They tell me to get something like a 14" instead of something like a 23".

So here is the question...

If you have a 14" barrel that shoots a paintball at 250 fps and a 23" barrel that shoots a paintball at 250 fps why would the 23" not shoot as far as the 14"???

The fps is measured when the ball exits the barrel so you would need to adjust the pressure depending on what barrel you have to make sure the ball exits the barrels at the same speed.

The 23" has more friction and you will end up using more co2 but I don't see why you would lose distance.

If you could help me it would be much appreciated!!!

THANKS !

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#### DaveC426913

Gold Member
If you are able to adjust the pressure so that the muzzle velocity in the 23 is the same as the 14, then yes indeed the distance will be the same.

#### NightSwimmer

Assuming that the exit velocity is equal, then aside from the 9 inches gained by barrel length, the distance achieved should be the same. The only factor that I can imagine that could make a difference would be the amount of spin applied to the paintball. I can see how the longer barrel might impart more spin. It seems to me that the spin must be in the correct direction in order to improve the overall distance achieved. I know that spin appropriately applied to a baseball can cause it to rise as it travels through it's trajectory. There is also the consideration of whether generic spin could increase or reduce friction (wind resistance) as the ball travels through the air. That is why golf balls have dimples.

#### DaveC426913

Gold Member
Assuming that the exit velocity is equal, then aside from the 9 inches gained by barrel length, the distance achieved should be the same. The only factor that I can imagine that could make a difference would be the amount of spin applied to the paintball. I can see how the longer barrel might impart more spin. It seems to me that the spin must be in the correct direction in order to improve the overall distance achieved. I know that spin appropriately applied to a baseball can cause it to rise as it travels through it's trajectory. There is also the consideration of whether generic spin could increase or reduce friction (wind resistance) as the ball travels through the air. That is why golf balls have dimples.
Spin from a barrel is around the axis of the trajectory - not perpendicular to the trajectory, as with baseballs or golfballs - and it is done to keep the slug aerodynamically stable, rather than tumbling. Balls are spherical, whereas slugs and (footballs) are not. Slugs will be subject to large drag forces if not kept spinning about their longitudinal axis.

#### Quisquis

Spin from a barrel is around the axis of the trajectory - not perpendicular to the trajectory, as with baseballs or golfballs - and it is done to keep the slug aerodynamically stable, rather than tumbling. Balls are spherical, whereas slugs and (footballs) are not. Slugs will be subject to large drag forces if not kept spinning about their longitudinal axis.
As a long time paintball player, I can say with confidence that you impart essentially no spin on a paintball with a rifled barrel. The liquid fill inside the shell acts just like water inside a glass. You can spin the glass, but the water doesn't spin. As soon as the paintball leaves the barrel, any spin imparted to the shell is lost to the drag of accelerating the fill, and there isn't enough mass in the shell to impart enough energy to maintain any significant overall rotation.

There are a couple of exceptions to what I just posted, but they have a different purpose than imparting accuracy and I'll get to them later.

Response to the OP:

Muzzle velocity is the ONLY thing that decides travel distance.*

The length of a barrel doesn't much matter with regards to accuracy. There are VERY minor improvements to accuracy that come with a longer barrel(According to tests done by the magazine http://www.actionpursuitgames.com/").

If you're really looking to improve accuracy, get a reasonably lengthed barrel (14-18 in) kit, and use good paintballs.

Using good paintballs: poor quality paintballs are not truly round. They have dimples in them, and they very in size. This leads to inconsistency from shot to shot so no matter how good your barrel is, you still won't know where your next ball is going to land.

Getting a barrel kit: Getting a barrel kit is important because no matter how good your paint is, it will NEVER be exactly .68 cal. A barrel kit has either inserts or backs to the barrel that very minutely in diameter to match the paint that you're shooting that day. Matching paint diameter with barrel diameter is the single largest thing you can do to improve accuracy.

Gotta catch the bus home from work, so I'll finish this later.

*flatline (will explain later)

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#### DaveC426913

Gold Member
As a long time paintball player, I can say with confidence that you impart essentially no spin on a paintball with a rifled barrel.
I know. I was simply explaining away NightSwimmer's hypothetical about a possible advantage of barrel-length. He said barrel-length in general might be useful to increase spin, to which I pointed out that spin on a sphere is not much use.

#### DaveC426913

Gold Member
Getting a barrel kit: Getting a barrel kit is important because no matter how good your paint is, it will NEVER be exactly .68 cal. A barrel kit has either inserts or backs to the barrel that very minutely in diameter to match the paint that you're shooting that day. Matching paint diameter with barrel diameter is the single largest thing you can do to improve accuracy.
So, it's like tied to the paintball batch?

#### NightSwimmer

I know. I was simply explaining away NightSwimmer's hypothetical about a possible advantage of barrel-length. He said barrel-length in general might be useful to increase spin, to which I pointed out that spin on a sphere is not much use.
I agree with your assessment of my hypothetical. I just thought that I would throw it out there for discussion. I can see how spin applied in the proper axis to impart lift on the ball might increase distance, but I hadn't considered the fact that the fluid center of the paintball would tend to negate any attempts to apply significant spin to the ball. It seems to me that it would be difficult to apply the spin via barrel geometry in the appropriate direction anyway.

I am not very knowledgeable about the sport of paintball, but I am surprised to hear that rifled barrels would be used. I have enjoyed shooting air rifles rather extensively. I have found that when shooting BB's, as opposed to cylindrical pellets, in a 177 cal. air rifle with a rifled barrel that the BB's tend to curve rather wildly. This results in poorer accuracy than can be achieved by shooting BB's from a smooth bore barrel.

#### Quisquis

So, it's like tied to the paintball batch?
yes, when you're using quality paint with a high degree of precision in the manufacturing process, each case of paint (2000 "rounds") will be nearly identical in diameter. In the case of paintballs, price really will dictate quality.

DaveC426913 said:
I know. I was simply explaining away NightSwimmer's hypothetical about a possible advantage of barrel-length. He said barrel-length in general might be useful to increase spin, to which I pointed out that spin on a sphere is not much use.
Getting back to the flatline(from the other post):

The flatline is a particular type of barrel in which the is useful spin is actually imparted onto the paintball. Instead of a rifeled barrel though, it is a curved barrel. It is shaped like a banana and starts angled 5-10 degrees(not sure the exact amount) above parallel to the ground. It gently curves towards parallel to the ground. This imparts spin on the paintball which is parallel to the ground and perpendicular to the axis of travel.

This spin actually creates lift, which although not helpful in accuracy, can be helpful in many other ways. Due to the low velocity (280-300 fps) of a paintball they have very limited effective range, but with the flatline you get an extra 100 or so with the same velocity.
The other advantage is that if you are playing paintball in the woods, you're shooting with a flater trajectory, and so you can avoid low hanging branches. This can improve perceived accuracy because more of your paintballs are making it downrange.

I think that's about all I wanted to say... so to sum up my two posts, these are the things you should take away.

Longer barrels do NOT reduce travel distance.

Longer barrels do little to improve accuracy.

Good paint is the one largest thing to improving accuracy.

Purchasing a barrel kit with multiple diameters is the best thing you can do to improve accuracy from the perspective if a barrel choice.

The flatline barrel may be a good choice because of it's added range and flatter trajectory if you are playing woods ball. It will not actually give you any better accuracy than any barrel kit though.

Barrel kits: http://www.pbreview.com/products/reviews/1415/" [Broken] (just a couple of examples)

Flatline: http://en.wikipedia.org/wiki/Tippmann#Flatline_Barrel_System

Paintballs: http://en.wikipedia.org/wiki/Paintball_equipment#Paintballs

One final note... other than the barrel and paint match, the best thing you can do to get your accuracy up is to use compressed air instead of CO2. CO2 is a fairly volatile gas, and as such it's pressure will drop during intense shooting. This will cause a falloff in velocity which of course will effect your accuracy. Compressed air with a regulator is your best option for consistent shot to shot velocity.http://en.wikipedia.org/wiki/Paintball_equipment#Propellants"

I think that covers everything you need to know. If you have any other questions, I'd be happy to answer them. Good luck in your search for the perfect setup.

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#### berkeman

Mentor
Very cool info, thanks. Flatline -- interesting concept.

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