Hughes "retro fit" lifter not pumping up!
So does that crescent shaped area let the oil in from the waist band hole to flow around to all the right places? I am not sure I am following your whole explanation...
Well, at least you found it.... frustrating.
I am not knocking Hughes in particular but when we got some new shafts and rockers, the shafts don't get the interior machining oil and debris (left form boring the center gallery in the shafts) cleaned out before the surface hardening process. It took FOREVER to clean that baked-in crud out of there... a real pain for the end user for skimping a simple cleaning step. (At least their instructions clearly inform you that you do indeed need to clean that gallery out before use.)