I am modifying my gen 2 Marauder .177 with a Huma regulator, Hill hammer, hammer spring and valve spring (Tim Hill is awesome, btw. Super helpful and quick responses to all my inquiries). Anyway, I have it all put together and there is almost nothing coming out of the barrel. I have the regulator with the gauge port and the gauge is reading almost, but not quite zero. I have had this thing apart and put back together several times.What could be wrong?