Crosman 2250 co2 cart stuck

This happened a few times with my 2250. I was able to fix it every time by cocking the gun, pointing the gun downwards, and pulling the trigger. The cartridge just falls out the tube. I hope it's as simple as that for you. Good luck!
As I (and others) have mentioned previously, the Diana Airbugs/Chasers and the Artemis CP1/CP2 CO2 guns have that oval shaped hole provided in the cartridge tube for "helping" to free a stuck CO2 cartridge. I have used this feature a few times to free stuck (stuck may be too strong of a word here) cartridges on all three of these guns. Handy little feature... I really don't see any problem drilling a carefully located hole in the Crosmans to mimic this feature. The cartridges VERY seldom stick, but when they DO, it is a simple matter to utilize that hole with a non-marring tool of some sort to free the cartridge. I do think a drop of PellGun oil on the cartridge tip prior to piercing is a good preventative measure to help prevent sticking, as well as to provide a small amount of lubrication to the gun's innards. I will have to try your idea about simply firing the gun to see if this works to free "stuck" CO2 cartridges on the aforementioned brands.