OK gents, I seems to have had no end of frustrations with the rifle I built, and here's a new one. The bolt catch on my rifle will work when there's a mag in the mag well. If I drop the mag, the bolt will stay back, but it hangs on by a thread. It is the same with the stock bolt catch, and a Phase 5 ambi bolt catch. When there is no mag in the mag well and I rack the bolt while pressing the LOWER part of the bolt catch to engage the bolt, it will not engage at all. And before you even ask, yes I know the difference between how to press the bolt catch to engage it, and to release it. When I swapped out my lower for another lower this past weekend, the rifle functioned perfectly. HELP!