Paintball

[Brassballs]

I knew the waist has a larger OD than the fins but don't you think they might expand when shot?

Since you guys might be doing some testing here's a couple other things I don't think has been brought up,I could be wrong.

How does a rifled barrel affect air efficiency? with 12ies.
At what point(shot count) does the build up in the barrel start affecting FPS?

[Crimson Death]

Rifling hurts efficiency from what I gathered.

[tymcneer]

Originally Posted by Brassballs

I knew the waist has a larger OD than the fins but don't you think they might expand when shot?

Since you guys might be doing some testing here's a couple other things I don't think has been brought up,I could be wrong.

How does a rifled barrel affect air efficiency? with 12ies.
At what point(shot count) does the build up in the barrel start affecting FPS?

These are valid points. The purpose is to raise questions like this.

Originally Posted by Crimson Death

Rifling hurts efficiency from what I gathered.

I am not sure. UV_Halo may be able to answer this question. My opinion is that it will use more energy to launch a ball, but that *should* translate into longer range and more stable flight, as it will be spinning when it exits the barrel.

Ty

[The Flounder]

Originally Posted by Crimson Death

Rifling hurts efficiency from what I gathered.

High performance is not always efficient! I would rather be driving a Bugatti instead of a Prius.

Of course if the rifling does not improve performance the previous statement means nothing in this conversation.

[timefreak17]

DO we also want to extend this discussion to scarab arms first strike rounds?

They are similar to Tiberius in every way...except
1) It looks like the OD of the paint ball lines up with the OD of the fins in the photos of the round
2) They are more uniform across the tip and look like semi-spheres rather than boob shaped

This may change the ability to start FS rounds to spin in the barrel with the help of grooving.

What I don't know is the material they are using for the round.
Or how strong/brittle it is?

Well I will watch this unfold since i don't have the experience to help move this discussion along. Keep up the good ideas and moving this discussion forward.

[The Flounder]

Right now I am trying to figure out how to determine if the fins spread out when the pressure hits the cupped section. The best idea I have right now is some craft type (soft and easy to scratch) paint on the fins. Send them through a rifled barrel as well as a smooth barrel and catch them out the other end for inspection. Not perfect because there could be some wobble but an even wear pattern should indicate the fins opening up to engage the sides of the barrel and the rifling. I am open to suggestions as to the marking method for the fins.

[PistolRogue]

I highly doubt there's any expansion, you can't even really squeeze the skirt and get it to flex by hand.

[alpha434]

Originally Posted by The Flounder

Right now I am trying to figure out how to determine if the fins spread out when the pressure hits the cupped section. The best idea I have right now is some craft type (soft and easy to scratch) paint on the fins. Send them through a rifled barrel as well as a smooth barrel and catch them out the other end for inspection. Not perfect because there could be some wobble but an even wear pattern should indicate the fins opening up to engage the sides of the barrel and the rifling. I am open to suggestions as to the marking method for the fins.

This would be valuable data... Including some knowledge about the wobble.


Scarab rounds should not be included in this conversation. They're a theoretical, and we can't work with that.

[uv_halo]

Originally Posted by The Flounder

...I have also recently found a possible indoor range that is about 150' long. (I had no idea one of my local paintball fields had an indoor speed ball field.)

Indoor range? Where? I'm in nova and couldn't find one within 4hrs.

Originally Posted by Brassballs

I knew the waist has a larger OD than the fins but don't you think they might expand when shot?

Since you guys might be doing some testing here's a couple other things I don't think has been brought up,I could be wrong.

How does a rifled barrel affect air efficiency? with 12ies.
At what point(shot count) does the build up in the barrel start affecting FPS?

Originally Posted by Crimson Death

Rifling hurts efficiency from what I gathered.

I agree, the tiberius rifling does hurt efficiency and the rifling itself doesn't seem to hurt consistency too much on it's own. Here's what I found- if using an 850PSI air system, when you crank the gun reg up to get the round up to speed through the rifled barrel, the reg is no longer in it's optimal adjustment range and it becomes less consistent. Using an air system reg significantly above or below 850 seems to alleviate the consistency.

As far as 12gr CO2 and rifled barrels, it is less efficient enough that Trinity didn't recommend the combo if I remember correctly.

Originally Posted by timefreak17

DO we also want to extend this discussion to scarab arms first strike rounds?

They are similar to Tiberius in every way...except
1) It looks like the OD of the paint ball lines up with the OD of the fins in the photos of the round
2) They are more uniform across the tip and look like semi-spheres rather than boob shaped

This may change the ability to start FS rounds to spin in the barrel with the help of grooving.

What I don't know is the material they are using for the round.
Or how strong/brittle it is?
They are not out yet but it seams like they will be soon.

I know there are some folks who are 'connected' to scarab saying that their rounds will come to market. To be honest, I have no idea given that the aero design of their prototype is a direct copy of Perfect Circle's, and I wouldn't be surprised if they got sued when they brought them to market.

So, I'd wait to speculate until they are available.

[Spider!]

A few of thoughts to add;

On an over-bored barrel the round should at least be bumping into the sides as it goes down the bore. If not, I would use that barrel anyway. When it bumps, it will be bumped to twist with the rifling. I don't see how you would not get some rotation.

Any rotation from the barrel is a jump start and should be a good thing if the round can stand it. Too much rotation (more than the angle of the fins) should be wasted unless you have a muzzle condition, which is next...

Porting and barrel length should matter (if any of this does). On a short bull barrel (no porting) the gas escapes forward of the round, which should at least delay the establishment of air flow over the fins, if not push them the other way. With the right amount of porting and barrel length, the round can exit with little or no blow-by.

Yes? Da? Si? o no?