At 4000 I can't imagine you're going to see much movement unless you have super clean backends.
The Velocity has a super light load of particle and was never recommended for anything more than light to light-medium.
I never had much luck with mine on higher volumes of oil, and that was at OOB, 800, 1000, and 1500.
Still, it was a good ball. My first was replaced due to crumbling filler. I used a different drilling on the replacement and didn't like it. Had it plugged and redrilled like the 1st, but never got the same reaction. I ended up giving it to my teammate this year and he's having good luck with it so far.