To play devil's advocate, what's to prevent you from condemning yourself to the same or even a worse fate when, using your own words, you've abused your gun?
Prior to the problems you're experiencing, did you rule out your ammo being the issue and not the inner barrel? As Rogerborg said, you should aim to run the heaviest BBs your hop can lift. A heavier BB should be more accurate at distance on the same gun because it has more mass to be less affected by crosswinds. When I play outdoors, to paraphrase Linda Evangelista, my primary won't get out of its case for less than 0.28g. For skirmishing, I wouldn't personally recommend 0.2g on a primary.