This is a bore sizing chart that will help you figure out which barrels will most likely work with what paint and visa-versa.

I have decided to go with Big Ball paint. Tom mentioned how paint these days is very brittle, and I know this stuff was the sturdiest paint I used in my 'mag, and actually the most consistent as well. I know there are probably always going to be leftovers from making paintballs, so Big Ball should always exist. The size of this ball is .688 to .690, so we will just say .689. Now, to find a is what I have been looking for at:

Lapco Big Shot
ACI ???
Perfect Bore by PMI

Here is what it says...the Lapco is around .689-a perfect match. Then there is the Perfect Bore, which is around .688-.690, another perfect match. The ACI is too big.

Has anyone tried any of these barrels? Has anyone used Big Ball paint with incredible accuracy with a certain barrel? I would like to get a barrel that is more efficient than my Xcel, and shorter....and I am not exactly sure why a 5-6 effective bore length would give a better tightness to shot grouping versus a longer barrel with some porting...I would like to know why this is...why does the abrupt stop creat better consistency? Is this abrupt stop the paintball going out of a barrel, or just the end of the first stage of a two piece? I am looking mostly for consistecy, that is my priority, so what effective bore length should I be looking for, and how does that relate to a barrel when is says 10" or 12" or whatever the overall length is?

Any help is appreciated!