What type of force and volume are you experiencing?
It may be difficult to actually measure the volume.. Maybe you can break it down into the size of the stream.. Light, medium, heavy and the amount of streams as well as contractions.

Without taking anything other than L-Arginine (4.5gm) a day and L-Ornithine (3gm), which I’ve taken for years.. I couldn’t tell you my anything about my volume other than its always been plenty.. I usually have 5 to 6 contractions and within those are two heavy streams usually number 2 and 3 “or” 3 and 4
If I go a few days without sex or ejaculating; those two big streams can go from her lower regions (when I pull out) to her neck, face and hair; every once and a while, we lie on our backs and mutually masturbate each other, I can shoot up to and sometimes over our heads.
If I’m having sex once a day, the distance is about a foot +/- (belly/breasts).

I’m interested in adding Pygeum to my daily routine to see the effects.