I'll tell you now that from my experiance, balls suck. Spherical objects are rarely used as projectiles now as a reason; nothing is more unpredictable than a sphere.
And I'm not sure how many people are gonna "conform" to this here.
But back to physics here...don't even get me started on spin. I've seen some crazy shit before, all pending on everything and nothing. Backspin theory? Yeah, it works. To a degree. Likewise with putting other degrees of spin on a ball. But when you do that, and you're working with something with so little mass, it's gonna be holy hell trying to control that after the barrel of whatever you're using. I've seen balls take some crazy turns of no reason at all; I've seen them also work perfectly fine. But just think back to the ol' days when they used molded lead balls in smoothbore barrels; there's a reason they changed to things like they use today. Now, let's not talk about the mass and velocity on all this shit, but still...balls suck.
Brass has a smoother bore than aluminum, by the way. Or that's what the old farts online say, atleast. I do know that it isn't used in firearms because of it's conductivity of heat, and how soft of a metal it is. Would be terrible for a barrel. Works fine for Nerf, though.
And if you want reusable paintballs, for any reason, use ReBalls. All other ones that are marketed suck, don't even try with them. ReBalls might cost a lot, but it's a quality product that's great to use.
If you're going ahead anyways, go for the CPVC. It's more availible (to the blind kids who can't seem to navigate a hardware store, atleast...), easier to work with, and easier to adapt to existing mods, ideally.
That's just my cynical take on the matter...carry on now.
EDIT: Oh, before I forget...don't bother with trying to cut grooves in the barrel or anything. None of that stuff is going to work at these velocities, trust me. Doesn't work in paintball, it's not going to work here.
Edited by Ragornocks, 07 January 2006 - 08:29 PM.