| Manufacturer | Byrna Technologies (USA) |
| Launcher Type | Rifle — semi-automatic |
| Power Source | CO₂ — 88g cylinder |
| Caliber | .68 caliber round ball |
| Projectiles | Kinetic, Pepper (OC), Max (OC+CS), Pro Training |
| Weight (loaded) | 6.13 lbs |
| Compliance | CA/NY compliant version available |
| Rail System | Full Picatinny (top and underbarrel) |
| Best Suited For | Home defense primary — users who need the highest shot count and range in the Byrna ecosystem |
Design & Build Quality
The Mission 4 is an AR-profile rifle with a design that prioritizes home defense staging over portability. The 88g CO₂ cylinder integrates into the stock assembly — a fundamentally different architecture than the grip-seated 12g cartridges of the TCR and Byrna handguns. This places the center of mass differently and contributes to the 6.13 lb loaded weight. The platform is available in a CA/NY compliant configuration, which modifies the stock and pistol grip profile to meet California and New York regulations on assault-style features — important for buyers in those markets.
Dual coupled 19-round magazines ship standard with the Mission 4 kit. The coupling allows rapid mag changes: when one magazine empties, you rotate the coupled pair and the second magazine seats without any tool. Full Picatinny rails (top and underbarrel) accept all standard AR accessories. The Mission 4’s fit and finish is Byrna’s best production quality across the lineup — appropriate for a $699 flagship platform.
Performance & Ballistics
The 88g CO₂ cylinder delivers a fundamentally different performance envelope than any 12g-based Byrna launcher. Average velocity of 325 FPS climbs to a maximum of 365 FPS at the beginning of the cylinder’s capacity; as the cylinder depletes, velocity settles into a consistent 325–330 FPS band before beginning to trail off near the end. At 100 feet, the Mission 4 maintains usable kinetic energy for impact rounds — more so than the TCR at equivalent range.
The 55-shot capacity changes the tactical calculation for a defensive deployment: unlike the TCR, which may exhaust its CO₂ supply after one extended engagement, the Mission 4 can sustain engagement through an entire defensive scenario without a cylinder change. For OC and Max round loadouts, the combination of 55-shot capacity, 19-round magazines, and 100-foot range creates a defensive deterrent profile with no close equivalent in the CO₂ less lethal category.
CO₂ System
The 88g CO₂ cylinder is purpose-built for the Mission 4 and is a different supply chain from the widely available 12g cartridges. Byrna sells 88g cylinders via its website; general retail availability (hardware stores, Walmart) is limited compared to 12g cartridges. Users planning home defense staging with the Mission 4 should maintain a supply of 88g cylinders — Byrna recommends replacing the cylinder after any significant training session rather than staging with a depleted cylinder.
Unlike the 12g Pull-Pierce system of Byrna handguns, the Mission 4’s 88g cylinder requires a dedicated threading/seating operation. The cylinder should be fully seated and verified before staging. Byrna recommends not leaving a pierced and partially depleted 88g cylinder in the launcher for extended storage periods; fresh cylinders are optimal for staged defensive use.
Projectile Compatibility
The Mission 4 fires the full Byrna .68 caliber projectile lineup: Kinetic, Pepper (OC), Max (OC+CS), and Pro Training. The 19-round dual coupled magazine configuration makes OC and Max round loadouts particularly practical — you can load 19 chemical rounds per magazine and maintain 38 rounds immediately accessible before any reload. For a home defense profile oriented around deterrence and area denial, this is a compelling combination.
The Mission 4 is compatible with the same projectile inventory as the SD, LE, and TCR — the .68 cal ecosystem serves all Byrna platforms except the CL. Bulk projectile purchasing for a multi-platform Byrna household benefits from shared inventory (excluding CL), and the Mission 4’s 19-round magazine capacity justifies maintaining larger projectile stocks than pistol-only users would need.
Known Issues & Limitations
- 88g CO₂ cylinders have more limited retail availability than 12g cartridges — supply chain planning required.
- At 6.13 lbs loaded, the Mission 4 is a staging platform only — not suitable for carry.
- 325 FPS average is modest for a rifle-form factor; HPA competitors at similar price offer significantly higher velocity.
- CA/NY compliant version may have feature restrictions that affect ergonomics — verify compliance specs for your jurisdiction.
- The 88g cylinder seating/threading process is more involved than plug-and-go 12g cartridge use.
Accessories & Upgrade Ecosystem
- 19-round coupled magazine pairs (additional sets available)
- 88g CO₂ cylinder refills
- Full Byrna .68 cal projectile lineup (Kinetic, Pepper, Max, Training)
- Optics and red dots (top Picatinny rail)
- Weapon lights and lasers (underbarrel Picatinny)
- Slings
- Hard carry case
Platform Summary
The Byrna Mission 4 is the ceiling of what the Byrna ecosystem offers for home defense staging. The 88g CO₂ cylinder’s 55-shot capacity, dual-coupled 19-round magazines, and 100-foot effective range create a package with no close equivalent in CO₂-powered less lethal. If you are staging a less lethal option as a primary home defense tool and want the highest round count and range Byrna offers, the Mission 4 is the answer.
The premium — $699 for the kit, plus ongoing 88g cylinder costs — is real. At that price point, HPA-based less lethal platforms with significantly higher velocity begin to appear. The Mission 4 wins on simplicity, CA/NY compliance, and the Byrna projectile ecosystem’s breadth; it loses on raw joule output compared to HPA alternatives. For buyers committed to the CO₂ + Byrna-ammo paradigm, it is the definitive platform.
