.55 cal paintballs ... new FPS limits?

[Jaan]

I just read with great interest in the new .55 cal paintballs that are being introduced.

Now, it occurred to me that a ball with less mass can be shot at a higher FPS and will hit with the same amount of impact force as a .68 cal paintball at 280 FPS. What would that number be though?

Here is what the press release says about the mass of the new paintballs:

"Q: What's the weight difference of SportShot ammo compared to .68 caliber balls?

A: SportShot ammo has a mass approximately 50 per cent lower than current .68 caliber RPS paintballs. The average .55 ball weighs 1.6 grams."

Obviously you would not just double the FPS because the force grows exponentially ... does anyone know the formula, or can figure it out for me?

Also ... it seems that shooting a smaller ball, at a greater FPS would give you greater distance and a "flatter" trajectory (which would be a big advantage). true or false?

You know what I'm getting at right ... true paintball sniper lol.

Seriously though, I'm just wondering what effect it would be if people started using smaller paintballs at a greater velocity. Already people are complaining that the smaller paintballs bounce a lot more, and there wouldn't be any reason to keep the chronograph limits the same as .68 cal paintballs ... in fact it would be scientifically wrong to simply pass along a safety standard when a major part of the equation is changed this significantly.

[skriptal]

Force is defined as F=MA Where M is Mass and A is acceleration
But what you feel on impact is the change in the Paintball's mometum on your body where its Kinetic energy (KE=.5MV^2) is being transfered to your body.

Momentum = Mass x Velocity
as given by the equation P=MV
So In theroy
If the Mass was 50% lower you could shoot it twice as fast and have the same change in momentum when it hits your body.

[Jaan]

So, if you're right, than a safe velocity for a .55 cal paintball would be 560 fps?

Man, that's far out.

[FinchMan]

but it's also transfering that energy over a shorter area of impact. .36 in^2 vs .23 in^2 .

[skriptal]

Ahh good point i did not even take that into consideration
there for i guess if it was a different mass such as half the mass of a 68 cal ball with 80% of the diameter you would be able to to shot it at 440 fps?

[FinchMan]

well, i think it would be less than that. Because it would be dependant on the area, not the diameter. So, thats .80 * .80, which is .64. So, 64% of 560 fps is 358 fps.

Thats assuming the impact pressure vs the surface area is linear. (is it?)

[slade]

Thats assuming the impact pressure vs the surface area is linear. (is it?)

yes. but remember, all of this could also be effected by the shape and composition of the ball. how thick is the shell? if its the same thickness of a .68 ball, then the smaller ball will be stronger and have a greater shell:fill ratio.

[bjjb99]

It may have been the result of poor production tolerances, but from what I recall the .62 and .50 caliber paintballs that were used back in the mid to late '80s were notoriously inaccurate and far more susceptible to wind and air turbulence than the .68 caliber paint.

Yes, some fields adopted higher velocity limits for these paintballs, with somewhere around 325 fps for the .62 cal paint and 350 fps for the .50 cal paint.

BJJB

[athomas]

The ball size is reduced by 50% in volume and mass, but only reduced by 35% in surface area. The initial velocity of one of these balls will be higher to achieve the same initial energy, but they will also be subjected to more frictional forces while in the air. So, they will slow down at a faster rate and generally be more suseptible to any forces that would alter the flight path.

[Arstron]

Speeding the paintball up for distant shoots will be fine, but what about when you bunker somone? I dont care what it is, you bunker somone thats a couple feet away with a object that is moving 500 fps and its going to hurt pretty bad. Just somthing else to think about...

[Jaan]

Well, that's the point isn't it? Would a smaller, lighter paintball travelling at a faster speed have the same impact force, or just the same as a heavier paintball travelling slower? Is the change in kinetic energy linear, or exponential?

You can't just assume what you said is true ... that's too dangerous. There must be safety standards that can be applied and followed. To change the size and weight of a paintball you should change the safety standards as well to reflect that. That's the right way to do it.

[pbfrek]

.68>.55
period
.


.68=More Weight=More Momentem=More Distance.

[slade]

.68>.55
period
.


.68=More Weight=More Momentem=More Distance.

umm, what? so youre saying you can throw a bowling ball farther than a baseball?

that may be a bad analogy, but you missed the entire point of the conversation, and youre considering one factor.

[Pneumagger]

that's not what he's trying to say. If you have two projectiles traveling at the same speed, the one with the larger mass has more energy. That means a lighter ball slows down faster.

With less mass camoes a lesser force needed to accelerate it in any direction. Sure, given ideal conditions, the smaller paint may travel as far, but will be more prone to wind and other factors.

This is the reason military snipers generally use larger bores at longer ranges. they are willing to sacrifice a bit of accuracy at shorter ranges for lots of consistency at very long ranges.

More massive paint will be more consistent. Period.

More than one area of comparison need to be addressed:

1) Impact of weight on consitint flight
2) Inital versus final speed dropoff
3) energy transferred to a finite area on a target. Smaller ball means more psi @ impact.
4) Less paint = smaller paint mark
...more?

[pbfrek]

Exactly.... If you get a bowling ball traveling at the same speed as a baseball, the bowling ball will travel further than the baseball.

Pneumagger makes some good points also.