Originally Posted by ThunderCactus
Generally half, same principle as lipo batteries actually
If you fill them cold, and they warm up, they may overpressure inside. But if they maintain room temp, then there's no problem storing them full.
I would suggest you shoot the gun once a month though. This prevents lubricants from gunking up and cycles the mags. It also ensures your mags stay gassed up if they have leaks too since you're filling them regularly
Great advice. I agree 100%.