I measured the axis tilt by measuring the diameter of the first oil ring. On the Black Hammer that seems to have the PAP at 6 7/16" x 7/16" up the oil ring diameter was around 11" and ran parallel to the grip line close to the middle finger hole. Since this seems to be an odd set of specs I did some...

Dear Group,

Sorry I forgot to mention axis rotation and tilt:
My axis rotation is 55*.
My axis tilt is about 18*

Dear group, I would like your input on what ball I need to fill a void in my arsenal. I bowl in a mix league at Brunswick National in Augusta, Georgia. The first third of the lane surface is a new synthetic surface while the last two thirds is an old synthetic lane surface. After reading the many ar...

In reading two articles on Gradient Line and Balance Holes one article says that the P1 location is always at the PAP with P4 being at the PSA. Another article says the P1 location is 6.75" from the PSA (P4 location) along the VAL. If one uses the 6.75" explanation the P1 location will not always be...