The Airsoft market can be overwhelming, especially when it comes to choosing the right BBs. With different weights, biodegradable options and tracer ammunition available, it can be difficult to know which is best for your Airsoft gun and playstyle.

This guide is designed for both new and experienced Airsoft players looking to make informed decisions about BB selection. Choosing the right BBs can significantly impact your Airsoft experience, affecting accuracy, range, and even the longevity of your equipment.

Read more to learn about Airsoft BBs, including how BB weight affects performance, the different types available, and how to choose the right ammunition for your next skirmish.

What are Airsoft BBs (BB pellets)?

Airsoft BBs are the ammunition used in Airsoft guns. Most are 6mm in diameter, which is the standard size for Airsoft pellets, and are manufactured in a range of different weights and materials to suit different guns and playing environments. Airsoft BBs are classified by weight, material composition, and special features.

While they may all look similar, choosing the correct BB can have a significant impact on your gun's accuracy, range and consistency.

One of the most important things to remember is always to buy high-quality BBs from a reputable manufacturer. Poor-quality BBs can have visible seams, inconsistent weights or imperfections that may damage your hop-up rubber, inner barrel or gearbox.

Why does BB weight matter?

BBs are available in a variety of weights, typically ranging from 0.20g up to 0.50g.

As the weight increases:

• Muzzle velocity (FPS) decreases

• Stability and accuracy improve

• Wind resistance improves

• Effective range generally increases

Although heavier BBs leave the barrel more slowly, they retain their energy better during flight and maintain their velocity over distance, resulting in a straighter, more predictable trajectory and greater consistency at range.

Why do heavier BBs reduce FPS?

Many players worry when they see their FPS drop after switching to heavier BBs, but this is completely normal.

Think of throwing a ping pong ball and a golf ball with the same amount of force. The ping pong ball leaves your hand much faster but quickly slows down and is easily blown off course. The golf ball travels slightly slower but carries its momentum much further, resulting in a straighter and more consistent flight.

Airsoft BBs work in the same way.

A heavier BB may produce a lower FPS reading on the chronograph, but it will often provide greater accuracy and consistency downrange.

Airsoft BB Weight Guide

0.20g BBs

0.20g BBs are the standard weight used by most Airsoft sites when chronographing Airsoft guns. They are ideal for indoor CQB games where engagement distances are short, and wind has very little effect.

They're also one of the most affordable BB weights available.

Best for:

• Indoor CQB

• Chronograph testing

• Entry-level Airsoft guns

0.25g BBs

0.25g BBs are one of the most popular choices among Airsoft players and offer an excellent balance between speed and accuracy.

Compared to 0.20g BBs, they provide a straighter flight path, improved consistency and better resistance to light wind, making them suitable for almost every standard AEG or Gas Blowback Pistol.

Best for:

• General skirmishing

• Most AEGs

• Gas Blowback Pistols

• Indoor and outdoor play

0.28g BBs

If you regularly play outdoors, 0.28g BBs are often the next logical step.

Their additional weight makes them less susceptible to wind and allows them to maintain a more consistent flight path over longer distances. Most modern Airsoft guns are capable of lifting 0.28g BBs provided the hop-up is adjusted correctly.

Best for:

• Outdoor skirmishes

• Players prioritising accuracy

• Well-set-up AEGs

0.30g - 0.32g BBs

These heavier BBs are generally used in upgraded rifles, designated marksman rifles (DMRs) and higher-powered Airsoft guns.

As weight increases, muzzle velocity decreases slightly, but accuracy and consistency continue to improve.

Best for:

• Upgraded AEGs

• DMR platforms

• Precision shooting

0.36g and above (for Airsoft sniper rifles)

BBs weighing 0.36g or more are primarily intended for high-powered bolt-action sniper rifles.

Their increased mass allows them to maintain stability over very long distances, making them the preferred choice for sniper platforms with properly tuned hop-up units.

Best for:

• Bolt-action sniper rifles

• Long-range precision shooting

Types of Airsoft BBs (Airsoft pellets)

Standard BBs

Standard BBs are the most common type of Airsoft ammunition and are suitable for the majority of players. They are available in a wide range of weights and colours.

Bio BBs

Bio BBs are biodegradable Airsoft pellets made primarily from polylactic acid (PLA) and gradually break down in natural conditions over time, unlike standard plastic BBs, which are made from ABS and can leave behind toxic chemicals as they decompose.

They are less harmful to wildlife and better for the environment. Many UK Airsoft sites require the use of Bio BBs as part of agreements with landowners, making them essential for woodland games.

Modern high-quality Bio BBs perform almost identically to standard BBs, but as with any ammunition, it's important to choose a reputable brand. Avoid leaving Bio BBs in contact with moisture for long periods, as this can cause issues over time.

Tracer BBs

Tracer BBs contain a fluorescent material that glows when illuminated by a tracer unit.

A tracer unit briefly flashes ultraviolet light as the BB passes through it, causing the BB to glow during flight.

Tracer BBs are ideal for situations where it’s easy to follow the BB in flight and see where your shots land:

• Night games

• Indoor CQB

• MILSIM events

• Watching your shots in flight

A visible tracer path can also help confirm whether a shot is likely to hit at longer distances.

They are available in both green and red variants depending on the tracer unit being used.

Frequently Asked Questions

Can I reuse Airsoft BBs?

No.

Once a BB has been fired, it may have picked up dirt, grit or suffered damage. Reusing BBs can damage your hop-up rubber, scratch your inner barrel or cause your Airsoft gun to jam.

What is the difference between 6mm and 8mm BBs?

The vast majority of modern Airsoft guns use 6mm BBs.

Some older or specialist Airsoft guns use larger 8mm BBs, but these are now relatively uncommon. Always check your Airsoft gun before purchasing ammunition.

Can I use metal, glass or ceramic BBs?

No.

Only use Airsoft BBs designed specifically for your Airsoft gun. Airsoft guns are not designed for metal or airgun-style pellets, and using them can damage internal parts.

Metal, glass, ceramic, paint-filled or other non-standard projectiles can seriously damage your Airsoft gun, invalidate its warranty and are prohibited at virtually every Airsoft site under rules covering Airsoft guns and similar weapons.

What BB weight should I use for my Airsoft gun?

As a general guide:

• 0.20g – Indoor CQB and chrono testing
• 0.25g – Most AEGs and pistols
• 0.28g – Outdoor rifles
• 0.30g–0.36g – Upgraded AEGs and DMRs
• 0.40g+ – Sniper rifles

Heavier and Bio BBs usually cost more, so it can be worth weighing budget against performance.

Ultimately, every Airsoft gun performs slightly differently, so it's worth trying two or three BB weights to find what works best with your setup. Where site rules allow, regular players may choose standard BBs to save money.

What do different coloured BBs mean?

BB colour usually does not affect performance.

Manufacturers often use different colours simply to help distinguish between different BB weights or product ranges, and some brands also use colour to separate product lines; white BBs are often easier to see in flight than darker options.

Colour alone does not indicate quality, so compare reputable brands rather than choosing by appearance.

I play CQB. What BB weight should I use?

For most indoor CQB sites, 0.20g or 0.25g BBs are the ideal choice. If you want a little more consistency from an electric CQB replica, 0.25g is often the better option. Heavier BBs generally offer little benefit at shorter engagement distances. Check site rules and stock Bio BBs if your indoor or mixed-use venue requires them, then search the range by BB weight once you know what suits your setup.