A Byrna works like an air pistol with one important change: the CO2 cartridge stays sealed until the first trigger pull. That single feature, Byrna's Pull-Pierce system, is what makes it usable for self-defense instead of only for the range, because the launcher can sit loaded and ready for months without bleeding pressure. This guide walks through the mechanism from cartridge to projectile, and what it means for how you use and carry one.
The power source
A 12-gram CO2 cartridge, the same kind used in air pistols and bike inflators, sits in the grip under a screw cap. On most launchers you pierce the cartridge when you install it, and from that moment the seal is leaking; a week later the launcher is flat. A Byrna does not pierce it on installation.
Pull-Pierce
The first trigger pull does two things: it drives a pin through the cartridge seal, and it cycles the valve to fire a round. Both happen in the same motion, so the first shot is a normal shot, and until that moment the cartridge is full. Load the magazine, install the cartridge, holster the launcher, and it is ready for months. After the first shot the cartridge is open, and it holds pressure for a magazine or so.
The magazine and the valve
The magazine holds five rounds in a tube. Each trigger pull opens the valve, releases a metered burst of CO2 behind the top round, and launches it. The mechanism is a double-action: the trigger pull does the work, there is no slide to rack and no cocking, and it fires every time you pull.
The projectile
A .68-caliber round on the SD, EP and LE, a .61 on the CL. Kinetic rounds are hard polymer that deliver impact; Pepper and Max rounds are shells that burst on impact and release an OC cloud. Muzzle velocity is enough for an effective range of about 60 feet, and the LE runs faster than the SD.
What it means for carry
- Carry it loaded with a cartridge installed; Pull-Pierce is designed for it.
- Carry a spare magazine with a spare cartridge, because the first cartridge is spent after one magazine. A mag cover PLUS holds both.
- Carry it in a holster that covers the trigger, because the trigger is the only safety step between holstered and fired: the SD/EP holster, LE holster or CL holster.
Byrna and the industry call these launchers less-lethal, not non-lethal: a hard projectile at close range or to the eye can injure someone, and a Byrna deserves the same handling rules as a firearm.
Frequently asked questions
Does a Byrna leak CO2 while stored?
Not before the first shot. The cartridge is sealed until the trigger pierces it.
How many shots per CO2 cartridge?
About one magazine of five, with some reserve. Carry a spare cartridge.
Do you have to cock a Byrna?
No. It is a double-action trigger; each pull fires.
Is there a safety?
A manual safety, plus the trigger pull. A holster that covers the trigger is the important one.
How fast does it shoot?
Fast enough for about 60 feet of effective range; the LE is the higher-velocity model.
The bottom line
CO2 in the grip, sealed until the first pull, five rounds per magazine, one pull per shot. Keep it loaded, holstered, and with a spare magazine and cartridge.
Related reading
What is a Byrna launcher?
What does a Byrna shoot?
Does the Byrna actually work?
