CYMA MWS/CGS GBB M4 Magazine, 30 Rounds

The CYMA CGS magazine is a 30-round metal M4 magazine for gas rifles built to the Tokyo Marui MWS standard, including CYMA's own CGS series. The magazine runs on green gas, is 175 mm long and weighs approx. 390 g, so it feels like a real STANAG magazine in the hand and in the mag pouch.

Green gas is filled directly into the magazine from a can, so there are no cartridges to change, and the pressure is lower than with CO2 – which is gentler on the bolt and seals in the rifle. For cold game days, when gas loses pressure, the magazine has an optional HPA inlet so it can run on compressed air via a line, with stable pressure regardless of temperature. The BB tube can be removed quickly, so you can reload with a pre-filled spare tube instead of loading BBs into the magazine in the field.

Green gas, HPA inlet and removable BB tube

Five features of the CGS gas magazine:

• Green gas operation: The magazine is filled in seconds from a gas can. The lower pressure compared with CO2 gives a soft bolt cycle and less wear on the rifle's internals.
• Optional HPA inlet: With an HPA regulator and line, the magazine can run on compressed air, which is not affected by cold in the same way as gas.
• Quick-release BB tube: The feed tube can be removed and swapped for a pre-filled tube, making reloading in the field much faster.
• Metal in STANAG format: The magazine body is metal and has the same external dimensions as a real M4 magazine, so it fits standard mag pouches.
• For MWS-spec GBBRs: Fits Tokyo Marui MWS M4/AR-15 gas rifles and CYMA CGS rifles built to the same standard.

Maintenance and safety

• Use green gas with silicone oil, or regularly give the fill valve a drop of silicone oil, so the seals do not dry out.
• Store the magazine with a little gas in it so the seals stay tight – but never in direct sunlight or high heat.
• Gas pressure drops in the cold. Keep magazines in a pocket close to your body before use, or run them on the HPA inlet.
• If you use HPA, the pressure must be controlled with a regulator and kept within what your rifle is designed for.