What Are Airsoft BBs Made Of? Materials, Manufacturing & Types

Airsoft BBs, also known as airsoft pellets, are small spherical projectiles that are shot from airsoft guns during airsoft games and competitions. Airsoft BBs come in a variety of materials, sizes, weights, and surface finishes. Understanding what airsoft BBs are made of and how they are manufactured can help players select the best ammo type for their needs.

Common Airsoft BB Materials

The most common materials used to make airsoft BBs today include:


The majority of airsoft BBs are made of plastic, typically biodegradable plastics like polylactic acid (PLA). Plastic BBs are inexpensive, lightweight, and can be manufactured very uniformly. They are suitable for most recreational airsoft uses. Some common types of plastic airsoft BBs include:

  • PLA plastic – Biodegradable plastic made from plant starch. The most common type is used today.
  • ABS plastic – Made from acrylonitrile butadiene styrene resin. More durable but less biodegradable.
  • PVC plastic – Made from polyvinyl chloride resin. More prone to shattering.

Bio-Degradable Materials

As airsoft has grown in popularity, more emphasis has been placed on using BBs made from bio-degradable materials. This helps minimize litter and environmental impact from spent BBs. Some newer materials used include:

  • PLA plastic – The most common biodegradable plastic polymer used.
  • Food-grade starch – BBs made from compressed corn, potato, or grain starch. Naturally biodegradable.
  • Polyethylene – A biodegradable plastic derived from sugar cane. Used for higher-end BBs.
  • Cellulose – Fiber-based material that is biodegradable. Used alone or in blends.


Glass airsoft BBs are still produced but are much less common today due to safety concerns. Made from soda-lime glass. Prone to shattering and not permitted at many fields. Mostly collector’s items now.

Metallic BBs

Some airsoft BBs are made from metals like copper or aluminum. Added weight can improve accuracy. But increased density limits the range. Niche ammo type with limited usage.

Manufacturing Process

Airsoft BBs go through a multi-stage manufacturing process to achieve consistent size, shape, weight, and surface finish:

Plastic Pellet Production

For plastic BBs, the raw plastic resin is first heated and injected into pellet molds under pressure. This produces uniform cylindrical pellets. Common mold types include:

  • Single-cavity – One BB molded at a time. Slower process.
  • Multiple-cavity – Makes multiple pellets per cycle. Higher throughput.

The pellets are then allowed to cool and harden before the mold opens and they are ejected. This yields plastic pellets ready for the next stage of shaping.

Spherical Shaping

The cylindrical pellets next go through a process to shape them into spheres. Two common methods used are:

  • Barrel tumbling – Pellets tumbled in a rotating metal barrel to knock off edges
  • Ball grinding – Pellets ground between a metal ball and grinding surface

Both techniques roll the pellets against abrasive surfaces or media to wear the edges down into a spherical shape. The pellets come out smooth and round.

Surface Treatment

For higher-grade BBs, additional surface treatment steps are used to improve roundness and smoothness. Techniques like:

  • Polishing – Abrasive polishing to make the surface glossier
  • Coating – Applying a thin oil, wax, or polymer coating
  • Metal plating – Depositing a thin metallic plating layer (e.g. copper, nickel)

These help give the BBs a more uniform surface finish and improve performance.

Sieving and Sorting

The finished spherical BBs are then sieved and sorted by size to achieve consistent dimensions and weights. Oversized and undersized BBs are filtered out. High-end BBs are individually inspected and weighed.

This ensures all BBs in a batch or bottle are within tolerance for weight and diameter. Typical sizes range from 0.2g to 0.43g.

Bottling and Packaging

The precisely sorted BBs are finally funneled into bottles and packaged for retail sale. Bottles contain from 100s to 10,000s of BBs depending on bottle size. Packages are labeled with details like material type, weight, and quantity.

Factors in Choosing BB Material

With different material options available, several factors come into play when selecting the best airsoft BBs:


Plastic BBs, especially biodegradable plastics like PLA, are the most affordable option. Higher-end polymers and bio-BBs cost more per BB. Players go through 1,000s of BBs, so cost is a big consideration.


Heavier BBs like metals can improve accuracy and range but limit how many BBs can be carried. Plastic offers a good balance of weight and quantity. Weights typically range from 0.12g up to 0.48g.


The hardness and durability of the material affect trajectory consistency and tendency to shatter on impact. PLA plastic has good toughness. Glass breaks easily.


Higher-priced BBs made with polished polymers, coatings, or metal platings offer the most uniformity and consistency for competitive shooters.

Environmental Impact

For outdoor play, biodegradable plastics or bio-BBs have less environmental impact and are preferred at many fields. Indoor fields allow any material.

Gun Compatibility

Heavier ammo may not feed well in all airsoft guns. Plastic BBs typically work universally across all airsoft gun models.

Considering these factors helps airsofters pick the right ammo for their budget, weapon platform, and playing style.

Types of Specialty Airsoft BBs

Beyond standard plastic BBs, some specialty varieties offer unique properties:

Tracer BBs

BBs with phosphorescent coatings that glow to help trace BBs in flight after firing. Lets players visually track shot placement and aim adjustment.

Glow-in-the-Dark BBs

BBs are infused with luminescent chemicals or coatings that absorb light and glow in the dark. For night games or low-light conditions. Help locate BBs on the ground.

Colored BBs

BBs dyed or coated in colors like red, green, and yellow. Allows using separate ammo types in the same gun. Mark teams or establish “zombie” ammo.

Metallic Coated

BBs with outer metal platings like copper, nickel, or gold. Enhances surface smoothness and weather resistance. Mostly for looks.

Pepper Spray BBs

Filled with liquid pepper spray that burst on impact. For self-defense purposes. Controversial due to potential misuse. Often prohibited.

Water Degradable

BBs are soluble in water. Break down when rinsed off the playing area. Help reduce leftover BBs in the environment after games. More expensive than standard bio BBs.

The variety of specialty ammo types allows more customized options for both function and appearance when playing airsoft.

BB Weight Standards

Airsoft BBs are manufactured and sold in a range of specific weights measured in grams (g). Following standards ensure proper velocity ratings and replica gun performance. Common weights include:

  • 0.12g – Ultra lightweight BBs. For test firing or target shooting.
  • 0.20g – Most common recreational weight. Used for plinking and informal target practice.
  • 0.23g or 0.25g – Normal weight for combat games. Balance of weight and affordability.
  • 0.28g or 0.30g – Heavier BBs used for more accurate longer range shooting in pro games.
  • 0.36g to 0.48g – High precision weights for maximum range and consistency for competitions.
  • 0.50g+ – Ultra heavy BBs only compatible with the most powerful upgraded guns shooting 500+ FPS. Very limited specialty use.

Heavier BBs require more energy to accelerate to the same velocity as lighter BBs. This affects the muzzle energy (FPS) ratings for airsoft guns. Players must use BBs aligned to their replica weapon’s specifications.

BB Size Standards

In addition to weight, airsoft BB diameters are standardized, with the most common sizes being:

  • 5mm – The most widely used BB size compatible with most airsoft guns.
  • 6mm – Slightly larger BBs primarily used in vintage and custom airsoft guns. Provides more air seal.
  • 8mm – A specialty large BB type occasionally used in custom weapons and grenade shells. Very limited adoption.

The industry standard 5mm and 6mm sizes ensure proper fit in barrel calibers across the range of airsoft guns on the market. This optimizes air seal for firing consistency.

BB Quality Grades

Airsoft BBs are manufactured to varying degrees of quality, with higher standards and more rigorous inspection testing yielding higher grades:

  • Standard Grade – Basic cheap BBs sold in bulk for very casual recreational use. Higher variability in shape, weight, and surface finish.
  • Field Grade – Affordable BBs still suitable for regular gameplay. Moderate quality control standards applied. The baseline grade most players use.
  • Competition Grade – Premium BBs put through more stringent manufacturing and sorting standards to achieve high uniformity and precision for tournaments and competitive matches. Worth the extra cost for serious players.
  • Match Grade – The highest standard BB production grade representing the top echelon of quality control. Very consistent size, weight, and finish for maximum precision. Used by expert sharpshooters.

Buying higher-grade BBs ensures getting the most consistent ammunition with the tightest manufacturing tolerances. This maximizes accuracy, range, and reliability for optimal airsoft performance.

BB Manufacturers

Several companies specialize in manufacturing airsoft BBs to serve the worldwide player base:

  • Elite Force – A popular brand known for their Bio and BioXLS biodegradable BBs made of plant-based materials. Also, offer non-bio BBs.
  • Valken – Leading supplier of their “Infinity” grade biodegradable ammo made of PLA plastic as well as non-biodegradable BBs.
  • G&G – Taiwanese company offering their precision grade BBs in multiple weights and materials. Available globally.
  • Airsplat – Retailer that produces their brand of BBs in partnerships with various OEM factories. Budget-priced.
  • Goldenball – Known for premium grade BBs made in Japan. Used in professional competitions. Among the most respected brands.
  • KSC – Another highly regarded Japanese brand producing BBs for over 35 years. Favored quality control.

With both budget bulk BBs and specialized high-end ammo available, players can find BBs tailored for any airsoft gun and application.

The Bottom Line

Understanding the common materials, manufacturing methods, weights, and grades of airsoft BBs allows players to select ammunition optimized for their replica firearm. While plastic BBs offer a good balance of cost, mass production, and adequate performance for most airsofters, those looking for maximum precision can benefit from using heavier and higher-quality BBs. With proper BB selection, players gain consistency and accuracy to elevate their game.

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