I got my 5# CO2 cylinder filled this morning. When I got back and hooked it up to the regulator, it read about 1600 psi. The tank still felt cold from filling; it had been 45 minutes or so, but it had been packed for safety in motorcycle luggage and, thus, insulated. Also, it was 7.2# heavier than when empty.
Should I be concerned about anything? My regulator had read 550 or so until the CO2 started running out. It read less than 1000 at room temp the first time I filled it.