Closed v. Open (Bolt)

[AGD]

The ball leaves the barrel in about 3 thousandths of a second. This is long before the gun starts moving anywhere.

AGD

[Lord Vader]

Great minds think alike, eh Tom? ;-)

If you need a nuclear engineer at AGD, lemme know.

[kilaueakid]

Quote
"The reason that handgun jump has little effect on handgun accuracy is simple: the bullet is traveling so fast that it leaves the barrel before the barrel jumps due to recoil"


So than this same info is true with paintball guns since the ball leaves long before the gun moves.

Now try squeezing off 9-12 shots a second on a handgun and tell me how accurate it is.

I think Tom holds the answer for better accuracy in paintball markers with items like there military paintball with the fins on the face of it. Paintball technology/design has to change before leaps and bounds are noticed in the accuracy department.

kila

[snipey]

Re: HAHAHA...

Originally posted by Jonny05
Wait a sec deded... how does a ball become deformed being pushed into a barrel??? Nothing is collideing in your gun when you fire because one object (the ball) is at rest. The ball has very little resenstence when struck by the bolt. So the ball will be put in motion by the greater force acting on it. After it is in motion it will want to stay in motion- the only other force is the gas, bore resistance, then the usual gravity/air resistance. If anything it will be the gas that causes the deformation because of its greater force. But here is the thing- balls can handle the force.

So what I'm basically saying is the bolts force will not do any harm to the ball because it is smaller compared to the force of the gas.

any arguements?

-JONNY

The ball does have resistance to the impact of the bolt, because the ball has inertia, which is the tendency of objects to forcefully remain at rest. The speed and weight of the bolt easily overcome the ball's inertian and (collision #1) send it into the barrel. The ball is then propelled (collision #2) by the gas. The paintballs inertia after it's hit by the bolt is still much less than the inertia of the expanding gas and the collision of the gas and paintball propell the paintball forward to allow the gas to continua to expand untill it reaches approx 101.3kPa (1 atm, 14.6 psi). Before the gass is there, the ball recieves the pressure equal to the gases pressure (up to 31027.5 kPa, 306.3 atm, 4500 psi). Both collisions have potential to deform the ball, with the gas being more powerful of a force, with a longer length of time to deform the ball.

notes and formulae for anyone else:
pressures are approximated to 1 decimal only

intertia = mass of object * velocity

1 atm(atmosphere) = 101.3 kPa (kiloPascal) = 14.6 psi

acceleration = force applied / mass of object
(I don't have the mass of a paintball, but plug this to find out the force applied to the paintball, if you do.)
so: am = f
( m/s2)(mass of paintball) = (force applied)

all units are metric (grams, meters, newtons, liter, etc.)

[314159]

i see that nobody has mentioned lock times. (the time from when you pull the trigger to when the gas starts pushing the paint past the breech). the shorter the lock time, the faster the response of the marker, and the more effective that it would be in hitting a moving object.

[Conqueror]

Snipey: The ball never receives anything close to 306 bar of pressure. More like 10 bar, at the most (according to AGD). Even if you somehow managed to get 4500 psi into the firing chamber of your gun without killing yourself, by the time it reached the paintball from the chamber it would have dropped considerably.

I'm not really sure why you listed all those equations; you didn't use any of them.

Peace.

CQ

[snipey]

i figured that if you were intelligent enough to get as far as my post, you would know that 4500psi is definitely not the output pressure of an air tank. remotes are only rated up to 3000psi, so if you at least know your gear you could make the assumption that the air is regulated right out of the bottle!!! the equations were posted because, at the time, i did not know the mass of a paintball. i left them for someone else to plug-and-play. let's stop nit-picking post and keep to the subject now, ok?

[DPB]

Open vs. closed accuracy

I only read through 3/4 of an argument between cockers and mags and accuracy on closed vs open bolts. Also, I read many factors which each side states. However, with real firearms you would put the gun on a benchrest and measure the MOA or Measurement of Angle. Basically this measurement (inches the aim is off-center at a certain yardage), tells exactly how accurate a certain gun is point-zero. Of course the measurement is only effective for certain documented factors: wind, temp, humid, nitro press, ball, bolt, reg, etc. Kickback or recoil is an X factor controlled and variable by the person firing the gun.

What is your take?

[apache]

Originally posted by BlackVCG
Minimag4me has the idea down. The bolt stem is designed so that the pressure is released at the end of the stroke. The current PT tip with the taper is designed to release the pressure over a longer interval. The old PT tip that was counterbored released the pressure in a quick burst. You can basically control how you want the pressure released and at what time by changing the design of the PT tip.

The I.D. of the PT tip is critical also. Take a spare PT tip and drill it out 1/16" larger and observe the results. It's quite interesting. :)

I don't have a drill so, Black, could you tell what the results are? Does the velocity consistency get any better or would the efficiency drop?

I have the old PT tip, would it help anything if I had the step inside smoothed?

[LSUMAG58]

i gotz a question

towards the top of the thread yall talk about the pre-coil and recoil of a mag decreasing its accuracy. what add-ons can decreas pre-coil/recoil and do you think that they would be worth getting

-LSU

[Minimag4me]

i think the only thing that can reduce precoil and recoil is the superbolt due to its lightweight nature.

[Rusty_Jones]

Originally posted by AGD
There is another comparison to make with the barrel jump scenario. Real handguns kick like a mule and jump several inches, by the same thinking they should not be able to hit ANYTHING! So why ARE real handguns accurate? Good Deep Blue question, answer that and you will know the answer to paintball gun kick vs accuracy.

AGD

Okay, I didn't take physics or any math past geometry so bear with this half-brained post...

Some law in physics states for every action there is an opposite and equal reaction. There are also exceptions to this law, which I'm not a physics major or rocket scientist so I don't know it very well but it's not hard to understand in practice. Which has something to do with recoil. Hammer hits the primer in a handgun, bullet is sent down the barrel. There's some rearward forces, energy mostly, and it's related to the muzzel energy. This energy is directly transferd to your hand and through it to your wrist, you wrist is now the recoil compensator. It angles back and upward, resulting in muzzel rise. Energy is still present and it travels to your elbow and shoulder. Gun manufacturers put holes in the end of the barrel to help step this down or a gunsmith does this. Most of the time it's just in the top, so the muzzel flash (still igniting gunpowder and gasses) is directed up, which is like a mini-rocket blast, pushing the barrel back down to ease the muzzel climb. The bullet is long gone and into it's target or flying until it loses it's velocity or hits something you didn't want to. Tom mentioned it takes some fraction of a second for the round or paintball to leave the barrel.
That's right, the projectile is gone before the rest of the forces at work happen.

The accuracy this relates to is the fact that you have to return your hand, wrist, elbow, or shoulder back to the correct position to shoot again. If you had no recoil (I'm not sure that's possible), you'd just have your natural inability to hold perfectly still to defeat to remove this movement from the factors working against you for accuracy.
So, like someone previously said, hold the gun tighter, it helps.


I'd like to address the Freak Barrel system real quick too.
The amount of room involved where there's any wiggle to make a difference is about the size of a paintball. So once the gasses come out the powertube, the ball is already against the sleeve on the inside, so there is no real wiggle to make the ball less accurate. So if you're considering a Freak, it's still a good purchase.

Hope this post makes some sense to someone besides myself, it is very late after all. :)

[Bob Mundon]

at under 50 yards a pistol will be virtually dead on accurate, the reason its inaccurate when you fire 6 shots a second is the user, not the gun. a gun will shoot where you point it at, if it missed, you did something wrong.

on of the reasons paintballs are inaccurate is they are a round shape, and round projectiles are not as effecient and build up more turbulence than a conical projectile, which is why bullets are conical. i know rifling in guns makes the bullet more stable but i remember hearing that it didnt do anything in paintball guns but i cant imagine why it wouldnt effect it.

[samvalentine]

rifling paintguns

it dose not work because paintballs are round soft liquid filled objects.
bullets are cylindrical and made out of metal. they are harder. they ride the rifling grooves.
paintballs do not. there like water balloons not bullets.

[pblunchbox]

um...little more research plz

When you qoute the Warpig article, make sure to remember that it was only tested to 25 feet. I agree that 25 feet is the AVERAGE fire fight for a front player. I on the other hand play back. My cocker shoots further at 285 that my mag.
It shoots further than my friends Angel. All with the same barrel and same paint. Why? well that i cannot answer. I can simply tell u that if you go to a chrono and put the barrel of all 3 guns on the little ledge you get the same reading +/- 3 fps but if you stand back 10 feet the cocker is shooting faster. No i again dont know why. Sorry for the not answerd questions. If you have the answer to that please feel free to let me know.
Oh yeah feel free to poke holes in my statements. i am simply going off what i have seen first hand.