The male end on the connector you posted to is
5/8" not 3/8".
By the wording
and am trying to thread the 3/8" male end into a 3/8" female end. It only gets 1-2 threads in and is tight.
It seems as if you're talking about the male side of the adapter you linked to, correct?
I use the same one to go from t-bar~> riser~> Shockmount with no issues.
What are you using it for?