Shooting 12+ BPS, mathematically speaking

[Tyger]

Can't sleep, so I decided to look some stuff up for the Web Dog Radio show I'm filming in... 6 hours. And you're gonna love this. This probably belongs in "Deep Blue", but that board scares me and I don't want to go there without armor and possibly a weapon...

You can "Solve" the time it takes for an accelerating object to travel a specific distance with this formula :




Now if you go to the root site of these formulas they have a handy HTML conversion of that formula for people like me who failed physics. I did some converting, and the numbers are kinda intresting. (Numbers truncated slightly)

From 0 FPS to 300 FPS, it takes a paintball .081 seconds to exit a 12 inch barrel from the initial resting position of the ball. It takes .088 to exit a 14 inch barrel, and .09 to exit a 16 inch barrel.

Given that 1/12 of a second is .83 (roughly) seconds, is it physically possible to have a ball still accellerating in your barrel while a second ball is loaded behind it IF you shoot faster than 12 balls per second? Mathematically, it is, at least according to what I've gotten. It's applied kinematics, yes, but it REALLY got me thinking. It could be a reason for shootdown too, if a ball is blocking some of the air leaving the valve as it's being loaded into the breach?

That'll get somoene's knickers in a twist...

-Tyger

post edited to fix a typo or two that was bugging me...

[Big'n slo]

Re: Shooting 12+ BPS, mathematically speaking

Originally posted by Tyger
It could be a reason for shootdown too, if a ball is blocking some of the air leaving the valve as it's being loaded into the breach?

That'll get somoene's knickers in a twist...

-Tyger

post edited to fix a typo or two that was bugging me...

I don't think this would cause shootdown in the mag. The bolt has to be seated before a ball can be chambered.

[athomas]

Your math is off a bit. The acceleration variable is dependent on the dynamics of the valve. The pressure which accelerates the ball gives the ball a non linear acceleration curve. Basically most of the velcocity is achieved in the first few inches of travel. When the variable rate of acceleration is used, the resulting time for a ball to exit the barrel is between 3 - 5 ms.

[Major Jam]

Athomas is right except Tom K. says that a paintball accelerates from 0 to 300fps and leaves the barrel in 6 thousands of a second (.006 seconds). I learned that from Tom's tip of the day on paintballradio.com (re: gun kick).

[joesf33]

THe artical is talking about barrels but it has references to velocity and acceration...

http://www.automags.org/resource/tech/tomstech/01_barrel_eff.shtml

[di96]

Wouldn't the air accelerating the ball follow behind it? so each ball you fire has the air pressure directly behind it.


like this A= Air o=ball

/<-Chamber End of Barrel--->\
o Ao Ao Ao Ao Ao Ao Ao Ao

something like that... kinda rough, but see what I am saying?

[di96]

which leads me to my other guess. When 2 balls load themselves in the barrel on a closed bolt gun, some air space is probably between them, maybe an inch or 2 of air. Therefor when you fire the marker the ball closest the bolt is accelerated, but the air between the 2 compresses acelerating the 2nd ball also. Allowing bot balls to shoot out of the barrel and not break in the barrel by colliding with one and other.

[Major Jam]

di96,

I was always under the assumption that there was and will never be more than one ball in the barrel at a time.

I always thought no matter how much you force feed paintballs into a gun. The one you just shot will always be out of the barrel before the next one gets in the breech.

[xXHavokXx]

Think about it, TK said that the ball will leave the barrel in 6 milliseconds, assuming you have a HALO with Victory board a ball will be loaded, every .0285 seconds, running at maximum speed. there will only be one ball in the barrel at a time. Then there are time losses for eye delays, bolt travel forward and backward, how fast you pull the trigger.

Also the acceleration wouldne be linear, its a differential equation, friction and pressure decrease due to expanding volume would have to be accounted for.

[Tyger]

Wel, goes to show you why I don't make paintguns, I just shoot 'em. Flawed thinking on my part.

Heh, and here I thought I was onto something...

-Tyg

[danheneise]

Whoa what was that, something just flew over my head... oh wait it was this whole thread. lol

i do like thinking about these things, but um... without the math part lol

-Dan Heneise

[la690]

Originally posted by di96
Wouldn't the air accelerating the ball follow behind it? so each ball you fire has the air pressure directly behind it.


like this A= Air o=ball

/<-Chamber End of Barrel--->\
o Ao Ao Ao Ao Ao Ao Ao Ao

something like that... kinda rough, but see what I am saying?

lol i must've been sleeping when we were taught that formula

[steveo356]

N i thought that paintball fill corroded our brains



Way to go tyger ida never had the patients to do that

[spadge67]

i have no input, but its very interesting, props on bringing that into my train of thought