Do not leave a 78 ungassed, your seals will dry out. The capsule are pierced at both ends of the tube and the gas is held in the tube. This keeps the seals from going hard. There is no seal where the seal butts up to in a 78. Whereas Crosmans are fed gas direct from the capsule one shot at a time, so a totally different method of gas release.
Take a look on UKCAF, we tend to know what we are talking about with reference to Chinese airguns.