I'm fairly new to the AR world, anyway I have a Bushmaster, 20"bull barrell flat top for about a year now. I have been shooting pretty much all Wolf 62gr. ammo without any issues until now. It's ejecting but not chambering the next round. I've been told a couple of different things could be wrong, the one that make the most sense is the gas tube being obstructed. Any other ideas or fixes out there? Can the gas tube be cleaned without removing it from the rifle?