Hammer has a ball for every condition (except for a cheap spare ball, unless you want to use your Rayzr here too)
There are 3 Heavy oil Hammers, the Anger, the Bite, and the NM.
I'm getting a NM drilled up, and its going to be my medium-heavy ball/go to ball. I had an Anger (just traded it for a Toxic) and I loved mine. It did great on oil. I had a pin under drill (approx. 5 1/2 inches to pap, pin under ring) and I ended up taking the surface to 1000 for PBA shots, but it would handle any oil.
I suggest cleaning your Anger (hot water bath, rejuvinator at proshop, hook again are the best choices) and taking it down a bit to see if it does the trick. Then you could see if you really need a new ball to handle heavy oil.
If you do need a ball to handle heavy oil, I'd take Blue's advice with the Bite layout.
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Weapons
Anger, Cell, Spare ball (for the pesky one left standing), Scout (rico!!), and No Mercy (on the way)
High Game-300
High Series-767