Problems with airsoft gun

[jaffe]

A friend yust gave me a airsoft pistol, the reason that he give me the pistol is because it's stuck . The problem is that the piston is not hanging in the seal when I pull teh slide back . Dus somewhone now how to fix this problem I have already lubricated every part in the gun.
Greetings from the Dutch, Jaffe

[singularity]

if its the model im thinking of the little plastic flap that would usually catch the piston has broken, if you take off the slide you should be able to see the witness marks. i don't really know if it can be fixed (without buying a new slide) but my ghettoness says try epoxying part of a washer in the place of the flap. i cant really explain it so you would be better off getting a new slide