There is , I think, a difference between saying matter behaves according to scientific laws, and saying scientific laws describe the behavior of matter. The descriptions are never complete and sufficient, although they are obviously sufficient to support technology and industry.
Everything is not a matter of measurement as you make it sound. If matter did not behave in a predictable manner science would be impossible. To postulate that scientific laws which have been proven to work numerous times prove nothing is to descend into complete skepticism of reality, the kind Hume went into. In a way this is a strange position for materialists to put themselves in since they claim that what you see is the reality and they are even denying that when they turn to skepticism.