In the world of airsoft today, there is still plenty of discussion about which barrel is “better” when comparing them. The problem is that most people are not looking at the whole picture when comparing barrels. Each barrel serves its purpose, and it is almost like comparing apples and oranges. I will not go into barrel length in this article, as it has already been covered in a previous article. This article will only talk about barrel bores.
Let’s start with tight bores, which typically come in two main flavors: 6.01mm and 6.03mm. For the purpose of this article I will define a tight bore barrel as any barrel from 6.00mm to 6.05mm. Your standard BB size will be 5.95+-, so the amount of air space between the BB and the bore of the barrel will be extremely slim, and thusly will reduce the amount of air loss and increase your FPS. If your gun was shooting 380fps with a standard barrel and you put a tight bore in it, you may see it jump to 400fps. While tight bore barrels are good for increasing fps, they may not do much for accuracy. This is because as the BB is traveling down the barrel there is less air space between the BB and the bore, so the BB will actually bounce around in the barrel. Tight bores are generally better for closer ranges.
Standard bore barrels are the barrels that come with guns from the factory. Aside from KWA, which uses a 6.05mm barrel, most of these barrels are going to be 6.08mm. This barrel is going to be the best balance between range and accuracy. In another article I explained that barrels do not directly impact accuracy; this is done by the hop up system you have (i.e. flat hop or r-hop.) The only thing to keep in mind when talking about the factory 6.08mm barrels is the quality. If you look down a precision tight bore barrel and compare it to a factory 6.08mm barrel, you will notice that the tight bore is extremely smooth and consistent. If you are going to use your stock barrel, you want to inspect it for imperfections. In a standard bore there will be more air space between the BB and the bore of the barrel, and the BB will be “cushioned” by the air around it. This will cause the BB to not bounce as much inside of the barrel. Standard bore barrels give you a nice balance between effective range and accuracy.
Wide bore barrels are not typically used in AEGs, but I can use them to prove my point. Wide bore barrels are anything above 6.13mm. ORGA airsoft makes 6.13mm and 6.23mm wide bore barrels. These are designed to give a large cushion of air between the BB and the bore of the barrel, as the BB is traveling down the barrel. This reduces the amount bouncing and friction of the BB inside of the barrel. For AEG applications these barrels will not work because of the amount of extra air loss will cause your FPS to decrease. You would have to do some serious modification to your gun to compensate.
Each barrel style does have pros and cons, so makes your decision based on the application. Wide bore barrels work extremely well in PolarStar guns because the user can increase the air pressure to compensate for the air loss. If you pair the correct barrel with a well tuned hop up system, you will be a force to be reckoned with on the field.