I built my first AR15 a couple months ago and have put about 50 rounds through it by now. Today I finally got my scope for it and went to sight it in. I shot about 6 rounds for groups at 25 & 50yds to make sure I was shooting consistently. However, then it all of a sudden stopped feeding and the bolt was noticeably not being thrown back far enough to catch the next round from the magazine. I tried different magazines and different ammo and got the same result. Next, I removed most of the oil that I had in the chamber (which was excessive), took the BCG apart entirely to de-oil/gunk it, then removed the gas block (which was actually wiggling slightly) and found that it looked like gas had been escaping around the barrel as there was a lot of carbon buildup all around the area. I cleaned the outside and chamber end of the gas tube, then resecured the gas block with some locktite, and proceeded to try again. No luck. Now it even jams and only ejects sometimes... Does anyone have any idea what else I could try to get this to work? If it helps, my BCG is Spike's Tactical. This is frustrating for me, especially since it worked so great before... Thanks!