i got a gsg and it had major jamming issues the first time i went to shoot it.
i came home and googled it and apparently alot of people had issues with overspray in the slide and on the top rails on the frame....sanded that all down, made it nice and smooth, took it back to the range and put 200 rounds through it, i got about 9/10 rounds to fire of the cheapest ammo the range had. pretty happy with it now. if i can get some better .22 i think it will be flawless especially after putting a few more rounds through it to break it in.