[L473ncy]

I've had a GBB shipped to me with about 3-5 shots worth of gas in it.

Everyone is different, some people store them with no gas, others a few shots worth and even others fully gassed up. Really it's your choice, but for me I keep mine slightly gassed up (probably enough for 4-5 shots at most). I'm of the belief that by keeping some gas and therefore pressure in the mag the seals are preserved better (I'm no engineer or anything, but it seems to make enough sense to me).