phil,
I have seen two bowling friends use a Neptune with radically different drills. They resulted in radically different ball reactions, almost as if they were throwing 2 different balls. The Neptune seems to react that way.
If I were you I'd try a longer and higher pin position, somewhere over the bridge area, depending on your PAP, putting the pin around 5", 5.5" or even 6" from the PAP, again, depending on exactly how high your rev rate is.
Also, you can try some surface modifications before re-drilling: sanding to 2000 grit and then to 4000 grit and then re-applying a good dose of polish to get back that high gloss shine. Standard finish is 1500 grit polish. Taht will add length to the ball.
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