pretty sure its only the first hit

I dont notice a tremendous damage in my pentas on birds when im standing behind or infront or to the side lol
"Pretty sure".
--- "I'm Pretty sure I didn't sleep with that woman sweetie, your eyes are playing tricks on you" ---
--- "I'm Pretty sure I am supposed to cut the red wire, here we go!" ---
--- "I'm Pretty sure genitel herpes isn't contageous, my doctor told me so" ---
Get the point?
Penta is such a random WS in most conditions, that it would take a large number pool of tests to show conclusive results.
Or you could just stand in front of the mob every time and be happy that you are doing X amount more damage.
Let's look at 20%(yes its 19% but 20 is easier to show numbers) damage... 1000 Vs 800, 2000 vs 1600
Would you notice a difference? Here's the kicker, Penta can do 2000 without being face-to-face. Such a random WS

.
A good test would be a person who has not merited this yet, doing a bird pt for a few hours with the same brd/cor. parse results.
This person then gets lvl 5/5 Overwhelm, grabs the same party, and parses again.
If the net increase of WS is 20%, bingo.
If the net increase is only 4% (20% / 5 = 4), then it would only be the first hit. (keep in mind these are "average" percents and not actual 100% correct numbers)
And another problem with testing the "first hit" theory, is how much damage does each "thrust" of penta thrust really do? Are all 5 hits equal damage? If i hit 1/5 for 300, would i have hit 2/5 for 600? Could I do a 1/5 for 800, and a 2/5 for 1600? There is no real way to test that, as i myself have done some 1 hit wonders for 900+.
I choose to believe it is the whole WS, as proven with the WS gorgets. Why would SE describe it as "weapon skill damage" if it was not so?
/long post off.