How long is the ball in the barrel when shot?

[Webmaster]

OK - first off I have mad props to Earon Carter - hes a god. But in the following interview he makes this statement:

From: http://www.paintball.com/features/st...acementID=1439

[synreal]

// disclaimer: few hard facts were used to come to the following conclusions, mostly opinion, take it is you may //

quick mental math says that your feelings are most likely correct. lets assume that the balls are being fired at 300fps muzzle velocity (or a foot every 300th of a second) that means that a ball already up to speed would clear the length of a 16" barrel in 4 milliseconds.

the average speed of the ball during the course of its travel down the barrel is going to be nowhere near its exit velocity (it spends most of its time down the barrel speeding up), and i lack the equipment, time and dedication to do adiquate testing, but an average barrel speed of roughly 1/3 to 1/4 muzzle velocity sounds completely reasonable, putting its time in barrel at about 16 milliseconds.

again, this is just me trying to logically think the problem through, but something tells me that their numbers are a bit off (not to mention dealing with how you would chrono a marker that could theoretically have atleast partial energy from anywhere from 1 to 4 bursts of air propelling any given paintball down range).

[hitech]

Here is the answer from Tom's Tech Tips:

Barrel Efficiency, Tech Tip #1

...The balls acceleration rate is approx. 50,000 feet per second to get to 300 feet per second in 10 inches. The entire barrel travel time is about 6 thousandths of a second... Although this may sound incredible if someone out there would like to do the math you will see that I'm close.

[Webmaster]

so... if its 6ms - that means you would need to shoot over 166 bps to get two in the same barrel...

Does this mean I win?

[hitech]

Originally posted by Webmaster
Does this mean I win?

Yup. No way are they spaced 3 to 4 inches apart!

[shartley]

[Thordic]

Uhm, is he kidding?

Hmm.. 300 fps... average 10 BPS for our purposes...

I count 30 feet between balls.

How about you guys?

[AGD]

Ahhhh such a good deep blue question...... If I were you I would focus on the 30 foot idea.

AGD

[shartley]

[ShooterJM]

Originally posted by Thordic
Uhm, is he kidding?

Hmm.. 300 fps... average 10 BPS for our purposes...

I count 30 feet between balls.

How about you guys?

Seems logical to me, I'm betting every one of us has run through a sustained firing lane without getting tagged. 3-4" spacing would be highly improbable to be able to run through.

[Miscue]

Earon: The first criteria, and most obvious, is to match the bore size with the
Larger bore size, longer barrel for the back
paint you are shooting. Players still forget that basic step. Rate-of-fire is another point to keep in mind. Back players shoot more paint, so they should look for larger bore diameters to increase their rate-of-fire. Front players need to shoot more precisely, like a BB, rather than more often. They should use smaller bore sizes.

Um... say whut?

[Vegeta]

I officially raise the BS flag.

[Top Secret]

Originally posted by Vegeta
I officially raise the BS flag.

No I do.

[EchoX]

Take note that the ball has to accelerate down the barrel, making the ball slow at hte beginning. Now calculus would have to play a part in this math.

[athomas]

There is a thread here in deep blue from a while back where we were debating the acceleration profile of a mag. What we discovered is that the ball is only in the barrel for a few milliseconds. I can't remember the exact numbers, but I think it was around 3.5ms.

Another factor that would limit the rate at which the balls could follow each other is the rate at which they drop into the breach, even with a warp feed or a halo. The warp feed and halo claim they can feed at about 22 balls per second. Thats about 4.5ms between balls.

Edit: Oops that's supposed to be 45ms between balls.

The first 3.5ms - 5ms is only about 12 - 16" because of the acceleration of the first ball. The breach feed rate of 45 ms is while the first ball accelerates to 300fps (~5ms) plus the time the ball travels at 300bps (~40ms) which translates into about 160 - 200". So the minimum distance between balls will be around 160" - 200" (depending on barrel) without adding any other factors if you could feed balls and pull the trigger at a rate of 22bps.

Edit: Explaination was not as clear as I would have liked. I also changed the numbers to reflect distance in inches instead of feet.