BBs are the bread and butter of airsofting. Without BBs, we'd just be idiots running around with expensive sticks. But what are BBs actually made of?
The term BB actually used to refer to a size of shotgun ammo. "BB" sized steel shots were 0.180 inches. The further up the alphabet you got, the bigger the pellet, up to OO size, also known as buckshot (because you use it to shoot deer).
BBs were known as birdshot because... well, obv. So original BBs were made of steel. Over time, the term "BB" stuck and became the name for any round pellet used in ordinance. This includes shots from mines, guns and grenades.
Fun fact! BBs aren't ball bearings and ball bearings aren't what you think they are either.
But back to airsoft BBs... The BBs we use in airsofting are made from plastic and weigh between 0.12g and 0.48g. Heavier BBs are less affected by wind, making them more effective for long range airsoft guns.
If you're looking to stock up on airsoft ammo, we have a wide range BBs available, including our very own Proball brand BBs.
Types of BBs
Biodegradable
When you're showering the landscape with your spray 'n' pray tactics, our lovely countryside could end up looking like a right state. Fortunately, biodegradable BBs are available.
Made of chalk and corn starch, these fully compostable BBs are much kinder to the environment. Most BB variants have a biodegradable option, for the environmentally-conscious airsofter.
Tracers
Tracer BBs glow in the dark. Ideal for night time skirmishes, they use a special device to charge the BBs by flashing them with a burst of light before leaving the barrel, so that they remain luminescent in flight.
This tracer unit is usually hidden from view, often disguised as a suppressor, or is included inside the magazine. Tracer BBs are useful for tracking your fire, but can reveal your position in the dark. If you want to stay stealthy, you should go for...
Non-traceable BBs
Like it says on the tin, these BBs are non-traceable. Well, mostly. Most airsoft BBs are white, making it easy to see the source of fire. Non-traceable BBs are black, or a similarly dark shade.
This makes it hard for your opponent to see where you're shooting from. But they have the disadvantage of making it hard for you to see where you're firing because you can't follow the path of the BB either.
Metallic
Metal BBs should not be used in airsoft guns. Though useful for target shooting, metal BBs are too dangerous for airsofting.
The added weight of metallic BBs reduces the effect of crosswind, imparting more accuracy when fired at longer ranges in outdoor environments where wind would significantly alter the trajectory of plastic BBs.
But since metallic BBs are so effective at going in you, we stick to plastic. Plastic BBs can hurt enough on their own!
Heavy Airsoft BBs
Heavy airsoft BBs offer a number of advantages over lighter variants. The increased weight means they are less affected by crosswind, making them more accurate when fired at long range in outdoor environments
They also have a higher kinetic energy on impact, making them more effective against targets. If you're looking to upgrade your airsoft gun to fire heavier BBs, you'll need to check the compatibility first. Some guns can't handle the extra weight and will break
Heavy BBs are usually 0.20g and above.
6mm Airsoft BBs
6mm airsoft BBs are the most popular size of BB. They're compatible with the vast majority of airsoft guns and offer a good balance between accuracy and power.
If you're just getting into airsofting, we recommend starting with 6mm BBs. Once you've got a feel for the game, you can experiment with different sizes and weights to find what works best for you.
BB Flight Physics
The weight of BBs impacts its performance. Heavier BBs provide greater accuracy, but a reduced range. A 0.2g BB travelling at 100m/s has kinetic energy of 1J.
Unlike paintballs that fracture and lose energy on impact, BBs provide a much smaller, but much weightier impact, despite the difference in size. This is why airsofting hurts more than paintballing and why we wear protective gear.
Here's a question you hear a lot when you're airsofting...
How hard does a BB have to hit to go in you?
The critical velocity required to penetrate your skin can be calculated using this formula: 
m is the mass of a BB, in grams. We are defining penetration here as the BB entering your skin to a depth of more than half of the BBs diameter (also known as "$#*! that hurt!").
So, a typical 0.20g airsoft BB will penetrate the skin at 136.7 m/s. 136.7m/s can easily be achieved by many airsoft guns at close ranges, so to prevent players being full of holes, many sites operate a zoning policy for when players end up too close together.
If you're playing CQB, wear your protection and just take it. For more information about BB physics, you can check out our FPS Calculator.
