WE M4/L85 Open-Bolt CO2 Blowback Magazine (30 Round) - Unstoppable Year-Round Performance

Don't let the British winter sideline your Gas Blowback Rifle. The WE Open-Bolt CO2 Magazine is the essential upgrade for players who demand consistent cycling and hard-hitting recoil, even when the temperature drops. Designed specifically for the WE M4 and L85 (SA80) series, these magazines swap out standard green gas for the higher pressure of a 12g CO2 bulb, providing the extra "shove" needed to keep your bolt moving when traditional gas mags start to suffer from cooldown. It is the definitive solution for those who refuse to switch to an AEG just because the frost has arrived.

Key Features and Performance

• Full Metal Construction - Robust, heavy-duty build quality that can withstand the rigours of aggressive skirmishing and tactical reloads.
• Open-Bolt Compatibility - Purpose-built for the WE M4, L85, MSK, and PDW Open-Bolt GBB systems for seamless fitment and feeding.
• 30-Round Real-Cap Capacity - Perfect for Mil-Sim enthusiasts and players who enjoy the tactical challenge of realistic ammunition management.
• High-Pressure Consistency - CO2 provides a more stable pressure curve than green gas, resulting in less FPS drop during rapid strings of fire.
• Easy-Load Design - A simple, threaded screw-cap at the base allows for quick 12g bulb changes during breaks in the action.

The "Pro" Take

The transition from Green Gas to CO2 is a total game-changer for the WE platform. While green gas is convenient, CO2 offers a significantly more violent and "crisp" blowback sensation that many GBB purists crave. It is particularly effective for the WE L85 (SA80) - the heavy bolt assembly in the bullpup frame requires substantial pressure to cycle efficiently, and CO2 provides that in spades. By switching to these mags, you aren't just gaining cold-weather reliability; you're increasing the felt recoil and ensuring that every trigger pull feels as authoritative as the first, regardless of the climate.

UK Spec and Site Performance

In the UK airsoft scene, these magazines are your best friend during the colder months. At Exeter Activity Centre, the dense Woodland Games environment often means playing in damp, chilly conditions where standard gas mags would "vent" or "freeze up" halfway through a skirmish. These CO2 mags ensure your M4 or L85 stays in the fight from the morning briefing until the final whistle.

When heading to HC2 for indoor CQB, the CO2 magazines provide a distinct psychological advantage - the muzzle pop is noticeably louder, which is incredibly effective for suppression in tight corridors. However, always remember to "Chrono" your rifle with these mags before playing. Because CO2 is higher pressure, it can increase your FPS/Joules; we recommend using an NPAS (Negative Pressure Air System) to ensure you stay within the standard 350 FPS / 1.13 Joule limit for UK sites.

Friendly FAQ

How many shots do I get per CO2 bulb?
Typically, you can expect to get around 2 to 2.5 full magazine cycles (approx. 60-75 rounds) from a single 12g CO2 bulb, depending on the ambient temperature and how fast you pull the trigger.

Will this fit the older "Closed-Bolt" WE rifles?
No, these are specifically designed for the modern "Open-Bolt" system. You can identify an open-bolt rifle by looking into the ejection port - if you see a clear chamber with a black nozzle, it is open-bolt; if you see a brass tube, it is the older closed-bolt style.

Do I need to maintain these differently than green gas mags?
Yes. Unlike green gas, CO2 does not contain silicone oil. We highly recommend applying a single drop of silicone oil to the tip of each CO2 bulb before inserting it to keep your internal seals lubricated and airtight.

Is it safe to leave a CO2 bulb in the magazine overnight?
It is best practice to remove the bulb after your game day. Leaving them under high pressure for extended periods can eventually deform the "O-rings," leading to leaks. Always vent the remaining gas safely before storage.