One of the main goals of paintball players is to continually improve their shot accuracy. A great way to do that is by changing the size of your barrels to accommodate the size of whatever paint you are using.
Some may think this doesn't apply to them because they always buy the same paint. However paint does swell or contract depending on the weather, so even if you do buy the same brand and make of paint every single time, it won't always fit in the same barrel exactly the same way.
One of the more common ways to counteract this and thus improve shot accuracy is by having a collection of barrel backs, with each back being a different size. You just match up the barrel back that works best for the paint you are shooting that day to a corresponding barrel tip and connect it to your marker. Barrels from Dye and other brands as well come in a variety of colors in both carbon fiber and glass fiber.
A different option that involves having and carrying around less pieces is to use inserts. You can buy a full one piece barrel for your marker and have a set of different sized inserts that fit into the back of the barrel that can be swapped out depending on the size of the paint you're using at any given time. Gog offers some great choices in that department. Inserts also work with two part barrel backs and barrel tips, like the Shaft FR series form Planet Eclipse.
There is also the option of a product like the Empire Freak Kit, which is one collection ready to buy with all the essentials such as different sized barrels and freak inserts. This is a good choice for players looking for something quick and easy.
For more details and specifics, check out the video below where we go in depth and go over all the specs of the different barrel options that can help improve your shot accuracy!