I have the WE HK 416, and ever since I installed the NPAS kit, I am having the BB jamming issue that other people have when they change the inner barrel (I didn't change mine). I am quite new with GBBR (still don't know how to adjust the hopup on this thing), but I didn't change anything but the NPAS.
Here is Ross' image describing the problem, so the question is anyone solved the issue yet?