Fill Nipple

Pressing a green gas bottle's nozzle down onto the fill nipple opens both valves at once, letting pressurised gas flow from the bottle into the magazine until pressure equalises or the bottle is pulled away; releasing it reseals the magazine's valve instantly so no gas escapes afterward.

A worn or dirty fill nipple O-ring is one of the most common sources of a magazine that won't hold gas overnight, and it's a cheap, quick part to replace compared to diagnosing a leak anywhere else in the valve assembly.

A drop of silicone oil on the nipple's O-ring during routine maintenance keeps the seal supple and is a cheap habit that noticeably extends how long a magazine holds gas between games.