I put new cartridges in the PPK and twinmaster. The twinmaster now works perfectly, but the ppk did it again, despite me putting some gun oil in. Its most bizarre . I've now run out of cartridges so will have to buy some more to see if it was just those being a dodgey batch.
I had a similar problem with my Walther Nighthawk. Even trying different brands of caplets including the lubed Walther ones didn't help - I thought the seal had gone.
A Very Nice Chap at Bury Gun Room told me that the brass screw seal on the drop-out CO2 mags have a tendency to work loose, and to try tightening the screw before fitting new seals, and it worked a treat!
If you can get to it on the PPK, give it a go first.
And buy lots of pellguin oil. A very nice chap on here sells it.
Have to agree...do not own a Co2 weapon without owning Pellgun oil...
Eric.