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How Does a Refillable CO2 Tank Paintball Gun Work?

The popularity of paintball has grown exponentially since it started in the 1980s. During all that time, the games and the arenas have also improved. This gives players more options to choose from than ever. Today, we will discuss why CO2 canisters are integral to paintball guns and how it all works.

rack of paintball guns

Different Types of Paintball Gun

There are several types of paintball guns; they come in either electric or mechanical models and are fuelled by either HPA (high-pressure air) or CO2 bottles.

The basics of both electric and mechanical are essentially the same; they both allow propellants to fire small paintballs at high speeds. The propellant fuel, in this case, can either be CO2 or HPA.

How Does a Paintball Gun Work?

Most paintball gun designs have a large container above the barrel where you store your paintballs. This component is officially known as the Feeder. This Feeder allows you to have many paintballs ready to fire rather than loading one at a time.

When pulling the trigger on a paintball gun, a small bolt in the Feeder pushes the ball into the barrel. A connected valve will release the compressed gas into the barrel and shoot the ball at your target.

You may be wondering what stops the ball from just rolling out when the gun barrel is facing the floor. This is where detents come in. Detents are tiny pieces of plastic that block the ball’s path until the gas is released.

close up of paintball guns

CO2 vs HPA

Both methods used to fuel paintball guns may seem the same at first glance, but significant differences have made CO2 the more popular choice.


CO2 had already been around awhile when manufacturers experimented with high-pressure air instead. This compressed air is simply the air we breathe, compressed and forced into a container at high pressure.

These HPA containers are pressurised at ratings of 3000 or 4500 psi. Depending on the design of your gun, it will then be released through the barrel at 450 to 850 psi.

One of the main features of HPA is that it can constantly remain in a gaseous state. This gives you a constant pressure for your propellant gas. Many HPA canisters will come with a pressure gauge, too, which helps know how much gas you have left in the tank.

Unfortunately, high-pressure air is currently quite expensive when compared to CO2. HPA tanks are also harder to get refilled as well as they require 3000psi, which is too high for your average supplier.


When paintball first started in the 1980s, all paintball guns used CO2. CO2 is an ambient temperature gas, but it turns into a liquid when compressed into its canister. When the weapon is fired, the liquid expands into a gas again and shoots the ball at high speed.

CO2 has a higher density than most compressed air; this allows CO2 canisters to be only rated at 850psi compared to HPA’s 3000 to 4500psi.

Refillable CO2 canisters are low cost, smaller and lighter than HPA, and can easily be refilled. As a result, they are an excellent choice for both beginners and established paintball companies.

paintball gun

Why Choose CO2?

With CO2 bottles being more affordable than ever, more paintball users choose refillable CO2 cylinders for their games. The CO2 tanks we supply are entirely refillable, so before your next game, you can simply send your paintball CO2 tanks back and get a refill.

Depending on the specifications of your paintball gun, you should get an average of 1056 shots for every KG of CO2 you have. Therefore, the 5KG cylinder we sell would give you around 1500 shots, and the largest we sell (34KG) offers a whopping 35,900 shots. Remember to consider how much ammo you regularly consume and buy an appropriately sized CO2 cylinder to match; you wouldn’t want to run out mid-game.

We recommend always getting a trained professional to refill your gas canisters. When attempting to fill a canister yourself, there is a risk of accidentally overfilling your canister past its specification. In addition, there is a chance the casing could crack and release the gas unpredictably and cause damage or physical injury.

International Bottled Gas Supplier

With spring well on the way, it’s time to start planning those outdoor activities that you’ve been missing all winter. Whilst there are many good choices to have fun outdoors, few can match the excitement of joining a paintball match.

At Bottle Gases, we can supply you with a range of CO2 cylinders for use with paintball guns. Our cylinders range from 5kg to 34kg, so as experienced bottles gas suppliers, we are confident that we have the perfect size for both paintball businesses and hobbyists.

If you’re unsure about your requirements, please get in touch online or call us on 01843 220596, and one of our expert team members will be happy to advise you.