What is an Airsoft BB?

An Airsoft Pellet or more commonly referred to as a BB is a 6mm (actual size is 5.95mm) in diameter spherical ball that is typically made out of plastic or biodegradable resin. They are offered in a range of weights that can go from 0.20g all the way up to 0.50g.

Types of Airsoft BBs


A biodegradable BB, also known as a bio BB, is constructed of a biodegradable resin such as polylactic acid (PLA). PLA is typically made from fermented plant starch such as corn, sugarcane, and other renewable resources.

Most outdoor fields require the use of bio BBs since sweeping is not an option and it helps protect the environment.


Plastic BBs are made from, you guessed it, plastic. Plastic BBs are primarily used when playing indoors, and should not be used outdoors.


A tracer BB is one that will become illuminated when exposed to UV light such as the one from a tracer unit. They are most commonly used when playing indoors, and at night games. They come in both biodegradable, and plastic materials.

What weight BB should I use? What are the best BBs?

This is a complex question to answer, so we've written an entire guide on the subject. Check it out here: What weight BB should I be using?.