Originally Posted by Mantelope
"duster" = HFC-134a = tetrafluoroethane = the correct low pressure gas; what most Japanese GBBs run on.
However, a lot of "air in a can" is actually = HFC-152a = difluoroethane = slightly lower pressure and bad for a number of seals. Don't use it.
The can will always say either tetrafluoroethane or difluoroethane somewhere on it.
+1 to that. You can't find tetrafluoroethance duster "over the counter" anymore. All the stuff you get nowadays is difluoroethance. You have to order the good stuff from industrial supply stores.
And using duster of any kind in a metal slide GBB won't even produce enough pressure to cycle your slide. You'll be left with the equivalent of an underpowered spring gun where you have to manually rack the slide with every shot.