Paintball

[Jordan]

Any advantage of one vs the other? Trying to decided how to build the Cane I might be getting one day.

While we're at it, any upgrades worth mentioning - QEV's come to mind - and are they worth it?

Jordan

[Heebs]

Less efficient, quieter.

[sdawg]

QEVs (quick exhaust valves) are only effective depending on where/how they're used. if the air flow ever reverses direction, like in the front chamber of an Ion, where the air is holding the bolt back, then the QEV reduces the amount of time for the air to empty out of the chamber, meaning less dwell time and higher efficiency. QEVs anywhere else on an Ion would be pointless because the air flows only in one direction.

Spiral porting, as I understand it, was a gimmick that a certain paintball manufacturer came up with in search of the holy grail of paintball known as "accuracy."

[brycelarson]

The porting thing is more an issue of volume of holes than layout. There's really been no proof that any layout helps. The double ported barrels tend to have a lot of holes - and on some designs those holes are big - which means a quieter, less efficient barrel.

If you take a barrel with one set of spiraled ports - but it had just as many holes of the same size, or holes in straight lines, but again, same number and size - all barrels would be similar in sound signature and efficiency.

As to accuracy - well, there's very little good evidence. All barrels, given a decent paint to barrel match, good polishing and starting clean perform to a level that, in my opinion puts them well within the accuracy potential of a crappy projectile like a paintball.

QEVs - couple of places you can use them - as stated, the front end of ION style guns - this will help the air escape quicker - thus speeding up cycle time a little. The second place is on really fast cockers - you can use them on the ram to speed up the cycle rate. However, this is only going to help if the rest of that cocker is really, really fast.

[flyweightnate]

I like both porting, and QEVs... I'm thinking single porting is plenty though.

On my cocker, I run a pair of QEVs, and it is noticeably faster. Makes it feel like something is getting done. There's a "Snap-snap" sound whenever I shoot, from the QEV membranes opening and closing, and it helps me not shortstroke as often, cuz the ram moves back just that little bit faster. QEV on the front end of the ram, not nearly as important. Some like to leave that one off, so the air cushion on the front of the ram helps prevent chops.

If you don't know if you want no porting, or single, or double, here's my take: Porting, as far as I've seen actually can improve accuracy a hint. Now, before I get mugged...
Suppose you have your gun tuned a little bit wrong, too much valve dwell or whatever. With an unported barrel, any excess gas pressure behind the ball blows by the ball at the muzzle, and can disrupt the path (at least in theory). Porting allows anything leftover near the tip of the barrel to exit out the sides, instead of the muzzle, precluding blow-by (if it actually happens) from happening. Personally, I think it works. Look at the Phantom- definitely a no-gimmick gun. The stock barrel, which is insanely accurate, isn't micropolished, or teflon coated, or even brass, but it does have about 2 inches of very small ports, right at the tip, with some grooves cut out to facilitate the air flowing to those ports.

Double porting, less noise than single (since there's less residual pressure at the muzzle) but less pressure means decreased velocity, and therefore efficiency. Single is a mix between unported efficiency, and double ported quiet.