N/A How should I store my airguns, with air or without air?

I have always shot my rifles down, not refilling before putting them away with great success. My daughter shot on her HS rifle team and now shoots in college. 10M air rifles like Walther, FWB, etc have removable air cylinders. They unscrew the air cylinders enough to not allow air into the reg and squeeze off a couple shots to release air from the reg at the end of each practice. They never have problems.
 
How should I store my airguns, with air or without air?
I store my FX with air above the regulator pressure, but not at max fill pressure. This puts less stress on the the tank, so the lifetime of the tank increases.

My Steyr lp50 at the other hand, I store without air. This gun has a removable bottle and is made to be stored without air.

Keep in mind, due to temperature changes the pressure changes inside the gun and creates a flexing stress on the tank. This stress is not much, but it is there. Also, keep in mind that alot of guns have orings that are set due to the pressure. If the pressure disapears, the orings can't get back to their original shape, which causes leaks. And at last, filling the tank from 0 to max pressure, creates alot more wear in the short term, compared to the flex due to the temperature variation. My advise, would be to make a compromise out of the three effects, based on the storage time.