Problem with my Dragun Please HELP!

[speedballer]

ok i have had the gun for a year now and the other day i put my co2 on and when i went to shoot it sounded like the gun just ran out a co2 and made that loud annoying noise untill i took off the tank so i went and got the tank refilled and put it back on and then i tried to shoot it and it sounded like it was out of co2 again so then i took the damn thing apart oiled everything and i replaced an o ring in the like ram air chamber or volumizer and it still wont fire correctly nothing is wrong with the tank cuz it fired fine on my other marker. PLEASE HELP thanks.

[schoolsukz08]

it mite be too cold and the co2 cant get up to a high enough pressure

[NC demolition]

check the valve seal, make sure its not leaking from anywhere, check the valve spring and bolt spring
if your bolt spring is old and soft and the valve spring isn't replace it... it may not be pushing striker into valve pin enough for proper amount of gas to get in. if the valve seal sticks put some oil on it. if it's worn out it could be leakin. simple way to fix this is flip it over so back is now front etc