Just wondering if anyone has ever wildcated a 6mm bullet on a 220 swift cartridge? Is that even possible? I am looking for a project rifle. I want to build a 6mm caliber gun. Maybe I should just buy a .243 or 6mm rem and save the trouble. But rounds I'm considering are: 6mm/284, 6mm-06, .243 AI. Any other 6mm's I should be looking at?