...80% of the time. The other 20%, a BB seems to jam itself right under the hole of the barrel, locking itself in place between the wall of the hop up chamber and the head of the cylinder, as shown here:
I have to take the mag out and poke the BB with my finger to get it to seat correctly:
I have tried different brand BBs and different mags. What could I do to fix this problem? I have access to a mill, so cutting the aluminum hop up is no problem. Could I perhaps make the chamber hole into the barrel slightly bigger and ramped?