An interesting topic.
Really don't know the answer. But would welcome any thorts...
I've got 3 CO2 pistols. Only used in Summer. Always leave the capsules in, stored in a dry room. Never used Pellgun oil, or ATF. As the latter is used in the harsh environment of auto gearboxes, never fancied using in my CO2 guns with (presumably) rubber/composite seals.
Like I said, don't know the answer - but would like to know the best way to keep them running for as long as my old Wobbleys!
ATB
Bru
Webley Mk3 x2, Falcon & Junior rifles, HW35x2, AirSporter x2, Gold Star, Meteors x2, Diana 25. SMK B19, Webley Senior, Premier, Hurricane x 2, Tempest, Dan Wesson 8", Crosman 3576, Legends PO8.