Beleive it or not, paintballs are NOT all the same size. They differ and vary by small amounts. When I refer to the size of a paintball I’m talk about an average size for any given brand.

You might think that all paintballs are all .68 caliber or .68 inches in diameter, BUT, if you were really to measure the size of paintballs you wouldn’t find very many that are exactly .68. They all vary from .67-.69.

So now that we know not all paintballs are the same size I’ve got another bit of news for you, barrels also are not all the same bore size. Some are bigger and some are smaller. Why? Well…I don’t know exactly why …all I know is that’s just how it is.

So what’s the big deal? Well if you get a paintball that doesn’t fit snugly in your barrel you’re going to get a lot of variations in your shots and you’re going to lose a tiny bit of efficiency in air useage. So basically you’re going to lose out on consistency.

The ideal situation is to have your paint be just about the same size as your barrel. A good way to test it is to detach your barrel from your gun and place a paintball in one end. If it just rolls through you’ve obviously got a bad match. Your pain shouldn’t roll right through, but should freely roll through when you blow it out. You want SOME resistance but not a lot. So with that being said, here’s a little example:

Paintborematch

If you want to get more of a visual on how this works I would suggest watching this as well:

Improving Accuracy

Tyger from webdog radio does a good job of explaining it.

So to sum it up, you’ll want to try different paint to see what works and what doesn’t. Ideally you might want to take your barrel with you down to the local paintball store and see if they’ll let you “Size up” your paint.
A bit about accuracy:

I’ve heard a lot of people talk about how accurate their gun is or ask me what an accurate gun/barrel is. Every time I hear this I just have to bite my tongue because nobody seems to get it. Accuracy is not a product of gear(well..to a certain extent) but more a product of skill and experience. If you take any two paintball guns and use similar barrels and paint they’re going to have about the same accuracy. You CAN get certain barrels that claim to be more accurate BUT the best thing you can do for your accuracy is get yourself a good paint to bore match. I’m not going to go into depth about barrel lengths and things like that because that’s been done to death just do a search.>