Steps to find your barrel: 
1) Find your favorite paint or the paint you plan to shoot the most, 
2) Find its "Bore Discription", 
3) Thumb through the barrel listing to find the barrels with the matching "Bore Description",
4) And pick one you like! 

If you already have an aftermarket barrel or are playing with your stock barrel, and you desire to find a good paint match, this chart can also help you. 

Steps to find a paint mach: 
1) Scroll down to find your barrel, whether in the aftermarket or stock barrel section, 
2) Find its barrel "Bore Description", 
3) Scroll back up to the Paint section and find a matching paint brand. 

If you want to get really technical, you can attempt to match the actual bore sizes, but in all honesty, this is not always completely accurate. 

The tried and true matching procedure is always the best when it comes right down to it.   Paintballs are naturally out-of-round, swell in hot/humid weather, shrink in cold weather, and just plain do what ever they want when they get old. the only sure test for paint/barrel match is to actually test the paint in your barrel: 

- Place a paintball in your barrel, 
- If it rolls out easily, your paint is too small, 
- If it does not roll out, blow in your barrel, 
- If you turn blue trying to blow it out, your paint is too big, 
- If you can easily or fairly easily blow it out, you have the right size paint.