Ammunition

6 mm BBs – the usual standard, but not all are equally well made

Classic airsoft ammunition has a diameter of 6 mm. “6 mm” is more of a guideline. High-quality manufacturers work with tolerances of ±0.01 mm or even tighter ranges. Such precision specifications may seem dry, but they are crucial if you have a setup that works with a tight barrel – such as 6.01 mm or 6.03 mm tightbores.

The more unevenly a BB is manufactured, the more lateral spin it produces in flight. This then ends in the typical “Why is the shot suddenly pulling to the left even though the hop-up is correct?” moment. So: uniformity, roundness (polishing level), and weight consistency are not optional, but real performance factors.

Materials – and why a lot can go wrong here

Airsoft BBs differ not only in weight and color, but above all in the material. Each has its advantages – and a few characteristics that need to be acknowledged.

Plastic BBs (standard)

The classic. Usually ABS or a similar plastic. These balls are robust, universally applicable, and inexpensive. Good standard BBs have very round surfaces, cleanly cut seams (preferably no visible seams) and a uniform inner core.

Important to know:

• Suitable for spring pressure, AEG and gas
• Good for magazines that are sensitive to material edges
• Extremely wide weight range available

Weaknesses:

• Not environmentally friendly
• In very hot environments, inferior BBs can become slightly softer

Bio-BBs (biodegradable)

Bio-BBs are usually made of PLA or PLA blends. They are often the mandatory choice for outdoor players because many playing fields now require them.

Strengths:

• Biodegrade under certain conditions
• Modern bio BBs are now just as round as plastic BBs
• Wide weight range, including heavy sniper weights

Honestly:

• They only biodegrade properly under certain environmental conditions (humidity, microorganisms, certain temperatures)
• Storage is more sensitive – they do not like extreme heat and UV light
• Some PLA blends are harder than plastic and can jam in the barrel of cheap brands

Aluminum BBs

This is where we enter a technically delicate area. Aluminum BBs are extremely stable, do not have the breakage behavior typical of airsoft BBs, and can actually be cleanly manufactured – but:

• They are hard.
• Really hard.

This means that hitting glass, laminates, or sensitive targets can cause damage that normal BBs would not produce. And when passing through narrow barrels, there is a higher risk of putting excessive strain on pistons, gears, or hop-up rubbers.

What they are good for:

• Special applications
• Personalized tests
• Some HPA setups, if you know what you are doing

What they are NOT good for:

• Airsoft contact games on normal fields
• Finely ground precision barrels
• Replicas with sensitive hop-ups

In short: Aluminum BBs are more for people who know exactly why they are doing this – and are aware of the risks.

Colored BBs

Colored BBs – i.e., not tracers, but classic colored plastic balls – look good, but usually have no technical advantage. On the contrary: Cheap color mixtures sometimes have a minimal effect on the surface.

Nevertheless, they do have their uses:

• better visibility at short to medium range
• more practical when several players want to use different ball colors
• good for fun games, less so for serious precision setups

Tracer BBs – light trails without muzzle flash

Tracer BBs are an exciting topic because they don't just have a visual effect. They contain phosphorescent material that is charged by a tracer (barrel attachment or magazine). This is a real advantage for night games or indoor matches – you can see the trajectory and impacts clearly.

Practical advantages:

• Hop-up adjustment is much easier in the dark
• You can recognize your own hits more reliably
• Extremely helpful for full auto in CQB

What you should pay attention to:

• The quality of the luminous material varies greatly
• Cheap tracer BBs often only glow for a very short time
• Some tracers are sensitive to moisture
• Tolerances vary more than with premium BBs

Heavy BBs – the underestimated science

Weight is a key issue. Most players start at 0.20 g or 0.25 g – and then often stay there for far too long. Weight influences:

• Flight stability
• Wind susceptibility
• Range
• Energy output
• Precision at distance

Here is a rough overview (without dogma, each setup reacts differently):

• 0.20–0.25 g: good for indoor use & low FPS
• 0.28–0.32 g: standard for outdoor AEGs
• 0.36–0.43 g: DMR and sniper ranges
• 0.45 g and above: for very precise, highly tuned sniper setups

BBs that are too light tumble, while BBs that are too heavy require stable hop-up rubbers and appropriate energy values.

Ceramic BBs (exotic, but they exist)

Yes, ceramic BBs exist, even if they are not very common. The reason is simple: they are hard, expensive, and not entirely safe from a technical standpoint. They are usually taboo for real playing fields. Nevertheless, they exist as a niche solution for certain tests and laboratory applications.

Gel BBs / Soft gel projectiles

Intended for gelsoft replicas, not compatible with normal airsoft guns. Water-filled hydrogel balls that burst on impact. Interesting for beginners and younger players – but technically a completely different system.

Why cheap BBs cause more damage than the packaging costs

One thing that many people only notice when something breaks: poor roundness, uneven cores, and internal air pockets can:

• Clog barrels
• Damage hop-up rubbers
• Strain gears
• Skew piston guides

A “cheap bag of BBs” can quickly turn into expensive gearbox damage.

What really matters when buying airsoft ammunition?

If we were to make a recommendation, it would not be “use brand X,” but rather:

• weight class suitable for your setup
• consistent manufacturing tolerances
• clean surface polish
• no visible seams
• right material for the application
• pay attention to the playing field (outdoors, bio is usually mandatory)
• only use tracers if you really need the feature