A Byrna launcher is not a toy, and it is not a simple machine either. Byrna says a traditional handgun has roughly 35 parts, while a Byrna has more than 110, and unlike a handgun it has to hold gas at 800 psi. That pressure is contained by a set of rubber seals and O-rings. When one of them dries out, cracks, or gets pinched, CO2 escapes and the launcher stops working the way it should.
The good news is that most leaks are preventable. This guide comes from the questions our service desk answers most often at the King Street store.
For the full list of supplies, see the Byrna Oiler and our CO2 cartridges in 8 gram and 12 gram sizes. New owners can also start with our getting started videos.
Where the seals are
You do not need to take a launcher apart to care for it, but it helps to know what you are protecting. The seals that matter most are:
- The face seal at the CO2 chamber. This is where the neck of the cartridge meets the launcher. It is the most common point of failure we see, usually from an over-tightened cap or a cartridge left pierced for too long.
- The internal valve O-rings. Several small O-rings seal the internal gas chamber and the valve that releases each shot.
- The transfer O-rings. These seal the passages that carry gas from the chamber toward the barrel.
Every one of these is rubber. Rubber that stays dry, cold, and under constant pressure loses its flexibility over time.
Cause one: over-tightening the CO2 cap
It is natural to think tighter means safer. With a Byrna, it does not. Cranking the end cap down can cut or pinch the face seal, and once that seal is torn, the launcher will leak no matter how tight the cap is.
Byrna's installation guidance is simple:
- Put the cartridge in neck first.
- Thread the end cap back on using the hex head.
- When you feel resistance, turn it one additional quarter turn and stop.
If you pull the trigger and hear gas leaking, Byrna's own troubleshooting step is to tighten one more quarter turn. If it still leaks after that, stop and bring it to us rather than forcing the cap further.
Cause two: leaving a pierced cartridge in the launcher
Byrna's patented pull-pierce design is one of the best things about the launcher. A new cartridge sits in the chamber unpierced, sealed, and ready. It is only punctured when you pull the trigger for the first shot. Byrna says that lets a launcher stay ready whether it has been sitting for a week, a month, or several years.
That changes the moment the cartridge is pierced. From then on, the whole system is under pressure until the cartridge is empty. When a launcher sits pressurized for long stretches, the seals are constantly loaded, and over time they flatten, dry out, and start to leak.
The habit to build: after a practice session, do not put the launcher away with a half-used, pierced cartridge in it. Follow your operation manual to safely empty and remove it, then load a fresh, unpierced cartridge for carry or storage.
Cause three: seals that were never oiled
CO2 is a cold, dry gas, and every shot pulls moisture out of the rubber it passes over. Oil is what keeps those seals soft enough to seal.
Byrna's guidance is that launchers need lubrication every 10 CO2 cartridges. There are two ways to do it:
- The oiler cartridge. Byrna includes one specially marked oiler CO2 cartridge in every box of ten, in both 8 gram and 12 gram sizes. It works like a normal cartridge, and when it is used, the oil spreads through the internal system and coats the seals. Use it as your tenth cartridge and you stay on schedule without thinking about it.
- The Byrna Oiler kit. The kit includes an oiling guide, an oiling tube, and a cleaning brush, with mineral lubricant oil. You place a few drops in the CO2 chamber with the guide, then load a cartridge and operate the launcher to spread the oil. The exact steps are in your Byrna operation manual.
How often you oil also depends on how many rounds you fire, how long the launcher sits between uses, and where it lives. A launcher kept in a hot car or near the ocean deserves a closer eye than one in a bedroom drawer.
One thing oil cannot do: it will not repair a seal that is already torn or cracked. Oiling is prevention, not a fix.
When your launcher already leaks
When a customer brings in a leaking launcher, we usually find one of these.
For a new launcher:
- A defect in the unit, which is a warranty matter.
- The CO2 cap was over-tightened and tore the face seal.
- The launcher was left pressurized and the seals dried out.
For an older launcher:
- Normal age-related seal wear.
- The CO2 cap was over-tightened and tore the face seal.
- The launcher was left pressurized and older seals gave out.
If your launcher will not hold gas, stop using it and follow the troubleshooting steps in your manual. You are always welcome to bring it to the store at 1773 S King St, Suite 201, or call us at (808) 489-2454 and we will help you sort out the next step.
Warranty and Byrna Care
Register your launcher with Byrna so your factory warranty is active. Registration, warranty claims, returns, and ByrnaCare extended protection all run through the Byrna Care Center. You can also reach Byrna customer service at (978) 868-5011.
A simple seal care routine
- Seat the cap to resistance, then one quarter turn. Never more.
- Do not store the launcher with a pierced cartridge in it.
- Use the oiler cartridge as every tenth cartridge, or oil with the kit.
- Check more often if the launcher lives in a car or near the ocean.
- Register your launcher and keep your receipt.
Frequently asked questions
Why is my Byrna leaking CO2?
The most common causes are an over-tightened CO2 cap that tore the face seal, a launcher left pressurized with a pierced cartridge until the seals dried out, or seals that have aged or were never oiled. A new launcher that leaks from day one may be a defect covered by warranty.
How tight should the Byrna CO2 cap be?
Thread the cap until you feel resistance, then turn it one additional quarter turn. Over-tightening can cut the face seal and cause the very leak you are trying to prevent.
How often should I oil my Byrna?
Byrna says launchers need lubrication every 10 CO2 cartridges. The easiest way is to use the oiler cartridge that comes in every box of ten as your tenth cartridge, or use the Byrna Oiler kit.
Can I leave a CO2 cartridge in my Byrna?
Yes, if it has not been pierced. Byrna's pull-pierce design keeps an unpierced cartridge sealed until the first trigger pull. Once a cartridge is pierced, do not store the launcher that way, because constant pressure wears out the seals.
Will oiling fix a launcher that already leaks?
No. Oil keeps healthy seals flexible, but it cannot repair a seal that is already torn or cracked. Bring the launcher in or contact Byrna about warranty service.