Not a lawyer but do t think they have a chance on the grandfathering. Different situation. The balls grandfathers were already approved and in production when they lowered the limit.
The limit was already in place for these.
Have a chance on the procurement and testing side. Where did the balls come from and how big was the sample size. Things like that.
And variance of the testing method since most of it relies on procedures done by hand, with measurements no where near as fine as 10000ths of an inch.
The only problem with your logic is that every manufacturer's bowling balls are measured using the same, industry accepted, way. That sets a standard. It is also in the rules that USBC has the right to make this determination.
Fair enough....then let them show the field testing done on the Hammer Taboo series. Or the Raptor series. Or provide the validation report on the sensitivity testing of their method.
If you pulled random samples of any bowling ball, there will be the same variance, yet they get to claim the number on the box. in front of a judge, they will not be able to demonstrate the accuracy of their measurement (i.e., sensitivity).
Selective enforcement does not fly. It is arbitrary and capricious. And with an inability to demonstrate VALIDATED sensitivity to the levels being discussed, then they would have a problem. This is why EVERY manufacturing industry has an allowable range of variance in products manufactured; including heavily regulated industries.
