It is just getting worn, it happens to all GBBs and all real semi automatic pistols.
Eventually the slide and frame will be worn to a point where they will need to be replaced, or you would need a new gun.
I would recommend that you put some really thick grease on the contacting areas in the slide and frame to make it last longer, the only other thing to help with wear besides not shooting it lol
Eventually the slide and frame will be worn to a point where they will need to be replaced, or you would need a new gun.
I would recommend that you put some really thick grease on the contacting areas in the slide and frame to make it last longer, the only other thing to help with wear besides not shooting it lol