Plastic - Steel - Lead or Rubber? The Ultimate Ammo Breakdown
Welcome back to Replica Airguns. I get asked all the time about which airguns hit the hardest, but a lot of people focus on the wrong attributes. They often look strictly at velocity instead of the raw energy and blunt force required for different tasks.
In this guide, we are breaking down the four main types of airgun ammunition: Airsoft, steel BBs, lead pellets, and rubber balls. The goal is to show you exactly what each ammo type excels at and where they fall short so you can choose the right tool for your specific needs.
6mm Airsoft: Safe Training and Plinking
Airsoft guns fire 6mm round balls, which are generally made of plastic, though you can find copper or zinc-coated variants. Because these are some of the lightest projectiles, ranging from 0.20 to 0.45 grams, they have the lowest overall energy and often lower velocities.
Best For: Airsoft is ideal for force-on-force skirmishes (with proper eye protection) because the lightweight rounds sting but do not penetrate the skin.
Practical Uses: They are great for safe indoor garage shooting without the risk of breaking windows, or for humanely chasing nuisance crows or vermin out of your yard without causing them permanent harm.
Platform Tech: Heavier airsoft rounds utilize backspin, or "hop-up", to float straight through the air for better accuracy, and they are typically fired from highly realistic, full-blowback gas or CO2 replica pistols. Most rifle Airsoft guns are AEG’s using a battery and spring setup which allows for easy semi and full auto operation.
Worst For: These are entirely ineffective for pest control (extermination) or any scenario requiring deep penetration or high impact energy.
4.5mm Steel BBs: Fast-Action Shooting
Steel BBs are 4.5mm in diameter, which translates to a .177 caliber round ball. Weighing in at approximately 5.3 grains, they are much denser than Airsoft rounds.
Best For: Steel BBs are fantastic for fast-action plinking, breaking glass bottles, and tearing up pop cans.
Platform Features: These are often used in 1-to-1 replica blowback pistols with drop-out full size magazines, giving shooters an authentic firearm feel for tactical manipulation practice.
The Dangers: Steel does not deform upon impact, meaning these BBs are highly prone to dangerous ricochets if you shoot at hard surfaces indoors or up close.
Worst For: Steel BBs lack the blunt force for home defense and are unethical for pest control as trey are a bit under powered and generally not as accurate as similar pellet guns.
Lead Pellets (.177 and .22 Caliber): Precision and Pests
Unlike round BBs, pellets are designed to be fired through a rifled barrel. Common sizes include .177 caliber (4.5mm, weighing 5 to 10 grains) and the much heavier .22 caliber (5.5mm, weighing 12 to 16 grains).
Best For: The soft lead engages the spiral grooves in a rifled barrel, providing unmatched precision and accuracy.
Terminal Ballistics: Because lead is soft, it expands and flattens upon impact, transferring its heavy kinetic energy directly into the target.
Practical Uses: This improved energy transfer makes pellets the ethical choice for small pest control.
Worst For: Pellet platforms are rarely designed as rapid-fire action shooters; they typically utilize slower single-shot (bolt actions) or rotary magazines that can require a bit of trigger finger strength to shoot quickly.
Rubber Balls (.43, .50, and .68 Caliber): Less-Lethal Blunt Force
This category represents the heavy hitters, firing massive projectiles that range from soft sponge rubber to dense steel-core balls, dust balls, and pepper balls.
The Power Factor: A .68 caliber home defense marker can produce upwards of 20-50 Joules (or roughly 15-35 foot-pounds) of energy with dedicated home defense styled Rubber Ball Guns.
Best For: The .68 caliber and high-powered .50 caliber options are explicitly designed for less-lethal home defense.
How They Work: Instead of penetrating, these massive projectiles dump incredible raw energy and blunt force directly onto the target, effectively stopping threats through extreme pain.
Training Options: The smaller .43 caliber variants are frequently chambered in realistic blowback replica pistols, making them excellent for tactical and paintball-style force-on-force training.
At the end of the day, picking the right Airgun comes down to matching the ammunition mass and energy to your target. You can find all the gear discussed here, from Airsoft replicas to less-lethal launchers, at the Replica Airguns Canada and US stores. Make sure you are subscribed to our channels across Rumble, YouTube, Vimeo, Instagram, X and Facebook for more detailed reviews and field tests.