I have a KWA ATP purchased in 2015 that has stopped cycling properly. With a freshly filled mag it would shoot but not push the slide back enough to load the next BB. After a number of shots it would cycle a bit better but still only ~85% success rate. The gas would run out after about less than 2 clips then it's same thing all over again. I've checked the nozzle assembly, oiled everything and mag's internals but the problem persists. I could start replacing parts but there's no telling if it'll all still be in vain. I'm wondering if the pistol is at the end of its service life and there's not much worth fixing? Anyone has experience with this pistol can share how long it lasted for you?